Sorttable.js (original) + bug fixes.

/*
  SortTable
  version 2
  7th April 2007
  Stuart Langridge, http://www.kryogenix.org/code/browser/sorttable/

  Instructions:
  Download this file
  Add <script src="sorttable.js"></script> to your HTML
  Add class="sortable" to any table you'd like to make sortable
  Click on the headers to sort

  Thanks to many, many people for contributions and suggestions.
  Licenced as X11: http://www.kryogenix.org/code/browser/licence.html
  This basically means: do what you want with it.
*/
var stIsIE = /*@cc_on!@*/ false;

sorttable = {

    init: function() {
        // quit if this function has already been called
        if (arguments.callee.done) return;
        // flag this function so we don't do the same thing twice
        arguments.callee.done = true;
        // kill the timer
        if (_timer) clearInterval(_timer);

        if (!document.createElement || !document.getElementsByTagName) return;

        sorttable.DATE_RE = /^(\d\d?)[\/\.-](\d\d?)[\/\.-]((\d\d)?\d\d)$/;

        forEach(document.getElementsByTagName('table'), function(table) {
            if (table.className.search(/\bsortable\b/) != -1) {
                sorttable.makeSortable(table);
            }
        });

    },

    makeSortable: function(table) {
        if (table.getElementsByTagName('thead').length == 0) {
            // table doesn't have a tHead. Since it should have, create one and
            // put the first table row in it.
            the = document.createElement('thead');
            the.appendChild(table.rows[0]);
            table.insertBefore(the, table.firstChild);
        }

        // Safari doesn't support table.tHead, sigh
        if (table.tHead == null) table.tHead = table.getElementsByTagName('thead')[0];

        if (table.tHead.rows.length != 1) return; // can't cope with two header rows

        // Sorttable v1 put rows with a class of "sortbottom" at the bottom (as
        // "total" rows, for example). This is B&R, since what you're supposed
        // to do is put them in a tfoot. So, if there are sortbottom rows,
        // for backwards compatibility, move them to tfoot (creating it if needed).
        sortbottomrows = [];
        for (var i = 0; i < table.rows.length; i++) {
            if (table.rows[i].className.search(/\bsortbottom\b/) != -1) {
                sortbottomrows[sortbottomrows.length] = table.rows[i];
            }
        }
        if (sortbottomrows) {
            if (table.tFoot == null) {
                // table doesn't have a tfoot. Create one.
                tfo = document.createElement('tfoot');
                table.appendChild(tfo);
            }
            for (var i = 0; i < sortbottomrows.length; i++) {
                tfo.appendChild(sortbottomrows[i]);
            }
            delete sortbottomrows;
        }

        if (window.jQuery) {
            var jTable = jQuery(table);
        } else {
            var jTable = false;
        }

        // work through each column and calculate its type
        headrow = table.tHead.rows[0].cells;
        for (var i = 0; i < headrow.length; i++) {
            // manually override the type with a sorttable_type attribute
            if (!headrow[i].className.match(/\bsorttable_nosort\b/)) { // skip this col
                mtch = headrow[i].className.match(/\bsorttable_([a-z0-9]+)\b/);
                if (mtch) {
                    override = mtch[1];
                }
                if (mtch && typeof sorttable["sort_" + override] == 'function') {
                    headrow[i].sorttable_sortfunction = sorttable["sort_" + override];
                } else {
                    headrow[i].sorttable_sortfunction = sorttable.guessType(table, i);
                }
                // make it clickable to sort
                headrow[i].sorttable_columnindex = i;
                headrow[i].sorttable_tbody = table.tBodies[0];
                dean_addEvent(headrow[i], "click", function(e) {

                    // console.log("Click Event");

                    if (this.className.search(/\bsorttable_sorted\b/) != -1) {
                        // if we're already sorted by this column, just
                        // reverse the table, which is quicker
                        sorttable.reverse(this.sorttable_tbody);
                        this.className = this.className.replace('sorttable_sorted',
                            'sorttable_sorted_reverse');
                        this.removeChild(document.getElementById('sorttable_sortfwdind'));
                        sortrevind = document.createElement('span');
                        sortrevind.id = "sorttable_sortrevind";
                        sortrevind.innerHTML = stIsIE ? '&nbsp<font face="webdings">5</font>' : '&nbsp;&#x25B4;';
                        this.appendChild(sortrevind);
                        // console.log("bsorttable_sorted")
                        return true;
                    }

                    if (this.className.search(/\bsorttable_sorted_reverse\b/) != -1) {
                        // if we're already sorted by this column in reverse, just
                        // re-reverse the table, which is quicker
                        sorttable.reverse(this.sorttable_tbody);
                        this.className = this.className.replace('sorttable_sorted_reverse',
                            'sorttable_sorted');
                        this.removeChild(document.getElementById('sorttable_sortrevind'));
                        sortfwdind = document.createElement('span');
                        sortfwdind.id = "sorttable_sortfwdind";
                        sortfwdind.innerHTML = stIsIE ? '&nbsp<font face="webdings">6</font>' : '&nbsp;&#x25BE;';
                        this.appendChild(sortfwdind);
                        // console.log("bsorttable_sorted_reverse")
                        return true;
                    }

                    // remove sorttable_sorted classes
                    theadrow = this.parentNode;
                    forEach(theadrow.childNodes, function(cell) {
                        if (cell.nodeType == 1) { // an element
                            cell.className = cell.className.replace('sorttable_sorted_reverse', '');
                            cell.className = cell.className.replace('sorttable_sorted', '');
                        }
                    });

                    sortfwdind = document.getElementById('sorttable_sortfwdind');
                    if (sortfwdind) {
                        sortfwdind.parentNode.removeChild(sortfwdind);
                    }

                    sortrevind = document.getElementById('sorttable_sortrevind');
                    if (sortrevind) {
                        sortrevind.parentNode.removeChild(sortrevind);
                    }

                    this.className += ' sorttable_sorted';
                    sortfwdind = document.createElement('span');
                    sortfwdind.id = "sorttable_sortfwdind";
                    sortfwdind.innerHTML = stIsIE ? '&nbsp<font face="webdings">6</font>' : '&nbsp;&#x25BE;';
                    this.appendChild(sortfwdind);

                    // build an array to sort. This is a Schwartzian transform thing,
                    // i.e., we "decorate" each row with the actual sort key,
                    // sort based on the sort keys, and then put the rows back in order
                    // which is a lot faster because you only do getInnerText once per row
                    row_array = [];
                    col = this.sorttable_columnindex;
                    rows = this.sorttable_tbody.rows;
                    for (var j = 0; j < rows.length; j++) {

                        var jrowCellItem = false;
                        var rowCellItem = rows[j].cells[col];

                        if (window.jQuery) {
                            var jrowCellItem = jQuery(rowCellItem);
                        }

                        var rowInnerText = sorttable.getInnerText(rowCellItem);

                        // Ensure we default this to ""
                        var rowInnerTextType = typeof(rowInnerText);
                        if (typeof(rowInnerText) === 'undefined') {
                            rowInnerText = '';
                        };

                        // Image Sortting
                        if (!rowInnerText.length && (jrowCellItem && jrowCellItem.length)) {

                            var jrowCellImageItem = jrowCellItem.find('img');
                            jrowCellImageItem = jrowCellImageItem.length > 0 ? jrowCellImageItem.first() : false;

                            // Only Get the SRC if, the IMAGE exists within this ROW
                            if (jrowCellImageItem && jrowCellImageItem.length) {
                                rowInnerText = jrowCellImageItem.attr('src');
                            };

                        };

                        // Update the ROW ARRAY with row_array_item
                        var row_array_item = [rowInnerText, rows[j]];
                        row_array[row_array.length] = row_array_item;

                    }

                    /* If you want a stable sort, uncomment the following line */
                    //sorttable.shaker_sort(row_array, this.sorttable_sortfunction);
                    /* and comment out this one */
                    row_array.sort(this.sorttable_sortfunction);
                    tb = this.sorttable_tbody;

                    // Check if this table contains zebra
                    if (jTable && jTable.length) {
                        var table_zebra = jTable.find('tr.alt').length > 0;
                    } else {
                        var table_zebra = false;
                    }

                    var zebra_key = 0;

                    for (var j = 0; j < row_array.length; j++) {

                        var RowArrayItem = row_array[j][1];

                        // Get jQuery revision of RowArrayItem
                        if (jTable && jTable.length) {
                            var jRowArrayItem = jQuery(RowArrayItem);
                        } else {
                            var jRowArrayItem = false;
                        }

                        // Re-Zebra the ROW
                        if ((jRowArrayItem && jRowArrayItem.length) && table_zebra) {
                            jRowArrayItem.removeClass('alt'); // Remove "alt"
                            if (zebra_key > 0) {
                                jRowArrayItem.addClass('alt');
                                zebra_key = 0;
                            } else {
                                zebra_key = zebra_key + 1;
                            }
                            RowArrayItem = jRowArrayItem.get(0);
                        };

                        tb.appendChild(RowArrayItem);

                    };

                    delete row_array;

                });
            }
        }
    },

    guessType: function(table, column) {
        // guess the type of a column based on its first non-blank row
        sortfn = sorttable.sort_alpha;
        for (var i = 0; i < table.tBodies[0].rows.length; i++) {
            text = sorttable.getInnerText(table.tBodies[0].rows[i].cells[column]);
            if (text != '') {
                if (text.match(/^-?[£$¤]?[\d,.]+%?$/)) {
                    return sorttable.sort_numeric;
                }
                // check for a date: dd/mm/yyyy or dd/mm/yy
                // can have / or . or - as separator
                // can be mm/dd as well
                possdate = text.match(sorttable.DATE_RE)
                if (possdate) {
                    // looks like a date
                    first = parseInt(possdate[1]);
                    second = parseInt(possdate[2]);
                    if (first > 12) {
                        // definitely dd/mm
                        return sorttable.sort_ddmm;
                    } else if (second > 12) {
                        return sorttable.sort_mmdd;
                    } else {
                        // looks like a date, but we can't tell which, so assume
                        // that it's dd/mm (English imperialism!) and keep looking
                        sortfn = sorttable.sort_ddmm;
                    }
                }
            }
        }
        return sortfn;
    },

    getInnerText: function(node) {

        // gets the text we want to use for sorting for a cell.
        // strips leading and trailing whitespace.
        // this is *not* a generic getInnerText function; it's special to sorttable.
        // for example, you can override the cell text with a customkey attribute.
        // it also gets .value for <input> fields.

        hasInputs = (typeof node.getElementsByTagName == 'function') &&
            node.getElementsByTagName('input').length;

        if (node.getAttribute && node.getAttribute("sorttable_customkey") != null) {
            return node.getAttribute("sorttable_customkey");
        } else if (typeof node.textContent != 'undefined' && !hasInputs) {
            return node.textContent.replace(/^\s+|\s+$/g, '');
        } else if (typeof node.innerText != 'undefined' && !hasInputs) {
            return node.innerText.replace(/^\s+|\s+$/g, '');
        } else if (typeof node.text != 'undefined' && !hasInputs) {
            return node.text.replace(/^\s+|\s+$/g, '');
        } else {
            switch (node.nodeType) {
                case 3:
                    if (node.nodeName.toLowerCase() == 'input') {
                        return node.value.replace(/^\s+|\s+$/g, '');
                    }
                case 4:
                    return node.nodeValue.replace(/^\s+|\s+$/g, '');
                    break;
                case 1:
                case 11:
                    var innerText = '';
                    for (var i = 0; i < node.childNodes.length; i++) {
                        innerText += sorttable.getInnerText(node.childNodes[i]);
                    }
                    return innerText.replace(/^\s+|\s+$/g, '');
                    break;
                default:
                    return '';
            };
        };

    },

    reverse: function(tbody) {
        // reverse the rows in a tbody
        newrows = [];
        for (var i = 0; i < tbody.rows.length; i++) {
            newrows[newrows.length] = tbody.rows[i];
        }
        for (var i = newrows.length - 1; i >= 0; i--) {
            tbody.appendChild(newrows[i]);
        }
        delete newrows;
    },

    /* sort functions
     each sort function takes two parameters, a and b
     you are comparing a[0] and b[0] */
    sort_numeric: function(a, b) {
        aa = parseFloat(a[0].replace(/[^0-9.-]/g, ''));
        if (isNaN(aa)) aa = 0;
        bb = parseFloat(b[0].replace(/[^0-9.-]/g, ''));
        if (isNaN(bb)) bb = 0;
        return aa - bb;
    },
    sort_alpha: function(a, b) {
        if (a[0] == b[0]) return 0;
        if (a[0] < b[0]) return -1;
        return 1;
    },
    sort_ddmm: function(a, b) {
        mtch = a[0].match(sorttable.DATE_RE);
        y = mtch[3];
        m = mtch[2];
        d = mtch[1];
        if (m.length == 1) m = '0' + m;
        if (d.length == 1) d = '0' + d;
        dt1 = y + m + d;
        mtch = b[0].match(sorttable.DATE_RE);
        y = mtch[3];
        m = mtch[2];
        d = mtch[1];
        if (m.length == 1) m = '0' + m;
        if (d.length == 1) d = '0' + d;
        dt2 = y + m + d;
        if (dt1 == dt2) return 0;
        if (dt1 < dt2) return -1;
        return 1;
    },
    //kryogenix sorttable - how to sort date columns that have empty cells
    //http://stackoverflow.com/questions/9815426/kryogenix-sorttable-how-to-sort-date-columns-that-have-empty-cells
    sort_mmdd: function(a, b) {
        mtch = a[0].match(sorttable.DATE_RE);
        if ((mtch == null) || (mtch == undefined)) {
            y = 0;
            d = 0;
            m = 0;
        } else {
            y = mtch[3];
            d = mtch[2];
            m = mtch[1];
        }

        if (m.length == 1) m = '0' + m;
        if (d.length == 1) d = '0' + d;
        dt1 = y + m + d;
        mtch = b[0].match(sorttable.DATE_RE);
        if ((mtch == null) || (mtch == undefined)) {
            y = 0;
            d = 0;
            m = 0;
        } else {
            y = mtch[3];
            d = mtch[2];
            m = mtch[1];
        }
        if (m.length == 1) m = '0' + m;
        if (d.length == 1) d = '0' + d;
        dt2 = y + m + d;
        if (dt1 == dt2) return 0;
        if (dt1 < dt2) return -1;
        return 1;
    },
    shaker_sort: function(list, comp_func) {
        // A stable sort function to allow multi-level sorting of data
        // see: http://en.wikipedia.org/wiki/Cocktail_sort
        // thanks to Joseph Nahmias
        var b = 0;
        var t = list.length - 1;
        var swap = true;

        while (swap) {
            swap = false;
            for (var i = b; i < t; ++i) {
                if (comp_func(list[i], list[i + 1]) > 0) {
                    var q = list[i];
                    list[i] = list[i + 1];
                    list[i + 1] = q;
                    swap = true;
                }
            } // for
            t--;

            if (!swap) break;

            for (var i = t; i > b; --i) {
                if (comp_func(list[i], list[i - 1]) < 0) {
                    var q = list[i];
                    list[i] = list[i - 1];
                    list[i - 1] = q;
                    swap = true;
                }
            } // for
            b++;

        } // while(swap)
    }
}

/* ******************************************************************
   Supporting functions: bundled here to avoid depending on a library
   ****************************************************************** */

// Dean Edwards/Matthias Miller/John Resig

/* for Mozilla/Opera9 */
if (document.addEventListener) {
    document.addEventListener("DOMContentLoaded", sorttable.init, false);
}

/* for Internet Explorer */
/*@cc_on @*/
/*@if (@_win32)
    document.write("<script id=__ie_onload defer src=javascript:void(0)><\/script>");
    var script = document.getElementById("__ie_onload");
    script.onreadystatechange = function() {
        if (this.readyState == "complete") {
            sorttable.init(); // call the onload handler
        }
    };
/*@end @*/

/* for Safari */
if (/WebKit/i.test(navigator.userAgent)) { // sniff
    var _timer = setInterval(function() {
        if (/loaded|complete/.test(document.readyState)) {
            sorttable.init(); // call the onload handler
        }
    }, 10);
}

/* for other browsers */
window.onload = sorttable.init;

// written by Dean Edwards, 2005
// with input from Tino Zijdel, Matthias Miller, Diego Perini

// http://dean.edwards.name/weblog/2005/10/add-event/

function dean_addEvent(element, type, handler) {
    if (element.addEventListener) {
        element.addEventListener(type, handler, false);
    } else {
        // assign each event handler a unique ID
        if (!handler.$$guid) handler.$$guid = dean_addEvent.guid++;
        // create a hash table of event types for the element
        if (!element.events) element.events = {};
        // create a hash table of event handlers for each element/event pair
        var handlers = element.events[type];
        if (!handlers) {
            handlers = element.events[type] = {};
            // store the existing event handler (if there is one)
            if (element["on" + type]) {
                handlers[0] = element["on" + type];
            }
        }
        // store the event handler in the hash table
        handlers[handler.$$guid] = handler;
        // assign a global event handler to do all the work
        element["on" + type] = handleEvent;
    }
};
// a counter used to create unique IDs
dean_addEvent.guid = 1;

function removeEvent(element, type, handler) {
    if (element.removeEventListener) {
        element.removeEventListener(type, handler, false);
    } else {
        // delete the event handler from the hash table
        if (element.events && element.events[type]) {
            delete element.events[type][handler.$$guid];
        }
    }
};

function handleEvent(event) {
    var returnValue = true;
    // grab the event object (IE uses a global event object)
    event = event || fixEvent(((this.ownerDocument || this.document || this).parentWindow || window).event);
    // get a reference to the hash table of event handlers
    var handlers = this.events[event.type];
    // execute each event handler
    for (var i in handlers) {
        this.$$handleEvent = handlers[i];
        if (this.$$handleEvent(event) === false) {
            returnValue = false;
        }
    }
    return returnValue;
};

function fixEvent(event) {
    // add W3C standard event methods
    event.preventDefault = fixEvent.preventDefault;
    event.stopPropagation = fixEvent.stopPropagation;
    return event;
};
fixEvent.preventDefault = function() {
    this.returnValue = false;
};
fixEvent.stopPropagation = function() {
    this.cancelBubble = true;
}

// Dean's forEach: http://dean.edwards.name/base/forEach.js
/*
    forEach, version 1.0
    Copyright 2006, Dean Edwards
    License: http://www.opensource.org/licenses/mit-license.php
*/

// array-like enumeration
if (!Array.forEach) { // mozilla already supports this
    Array.forEach = function(array, block, context) {
        for (var i = 0; i < array.length; i++) {
            block.call(context, array[i], i, array);
        }
    };
}

// generic enumeration
Function.prototype.forEach = function(object, block, context) {
    for (var key in object) {
        if (typeof this.prototype[key] == "undefined") {
            block.call(context, object[key], key, object);
        }
    }
};

// character enumeration
String.forEach = function(string, block, context) {
    Array.forEach(string.split(""), function(chr, index) {
        block.call(context, chr, index, string);
    });
};

// globally resolve forEach enumeration
var forEach = function(object, block, context) {
    if (object) {
        var resolve = Object; // default
        if (object instanceof Function) {
            // functions have a "length" property
            resolve = Function;
        } else if (object.forEach instanceof Function) {
            // the object implements a custom forEach method so use that
            object.forEach(block, context);
            return;
        } else if (typeof object == "string") {
            // the object is a string
            resolve = String;
        } else if (typeof object.length == "number") {
            // the object is array-like
            resolve = Array;
        }
        resolve.forEach(object, block, context);
    }
};