Javascript Calendar v2

function Calendar(inVarName, inCurrent)
{
    var dtmToday = new Date();
    dtmToday = new Date(dtmToday.getFullYear(), dtmToday.getMonth(), dtmToday.getDate());

    var dtmCurrent = inCurrent;
    var arrMonths = new Array('Januar', 'Februar', 'Marts', 'April', 'Maj', 'Juni', 'Juli', 'August', 'September', 'Oktober', 'November', 'December');
    var arrDayNames = new Array('M', 'T', 'O', 'T', 'F', 'L', 'S');
    var strVarName = inVarName;

    var arrActiveDays = new Array();

    var objBoxCalendar = document.getElementById('BoxCalendar');
    var objWrapper = null;
    var objNaviLeft = null;
    var objCalendarYear = null;
    var objNaviRight = null;

    this.create = function ()
    {
        if (objBoxCalendar)
        {
            CreateHeader('DayView');
            this.viewDays(dtmCurrent);
        }
    }

    this.viewDays = function (dtmStart)
    {
        dtmStart = new Date(dtmStart);
        if (dtmStart.getDate() > 1)
            dtmStart.setDate(1);

        for (var i = objWrapper.childNodes.length; i >= 0; i--)
        {
            var objChild = objWrapper.childNodes[i];
            if (objChild)
            {
                if (objChild.className != 'CalendarRowNavi')
                {
                    objWrapper.removeChild(objChild);
                }
            }
        }

        var objCalendarRowDays = document.createElement('div');
        objCalendarRowDays.className = 'CalendarRowDays';
        objWrapper.appendChild(objCalendarRowDays);
        for (var i = 0; i < arrDayNames.length; i++)
        {
            var objCalendarCell = document.createElement('div');
            objCalendarCell.className = 'CalendarCell';
            objCalendarCell.appendChild(document.createTextNode(arrDayNames[i]));
            objCalendarRowDays.appendChild(objCalendarCell);
            objCalendarRowDays.appendChild(document.createTextNode('\n'));
        }

        var intDaysInMonth = DaysInMonth(dtmStart.getFullYear(), dtmStart.getMonth());

        //Set the correct text and link on the top field
        while (objCalendarYear.hasChildNodes())
        {
            objCalendarYear.removeChild(objCalendarYear.firstChild);
        }
        objCalendarYear.appendChild(document.createTextNode(arrMonths[dtmStart.getMonth()] + ' ' + dtmStart.getFullYear()));
        objCalendarYear.setAttribute('onclick', strVarName + '.viewMonths(\'' + new Date(dtmStart.getFullYear(), dtmStart.getMonth(), 1) + '\')');
        //Do the same for the navigation buttons
        objNaviLeft.setAttribute('onclick', strVarName + '.viewDays(\'' + new Date(dtmStart.getFullYear(), dtmStart.getMonth() - 1, 1) + '\')');
        objNaviRight.setAttribute('onclick', strVarName + '.viewDays(\'' + new Date(dtmStart.getFullYear(), dtmStart.getMonth() + 1, 1) + '\')');

        //Fill the first row with blank fields until we reach the starting point
        var objFirstRow = document.createElement('div');
        objFirstRow.className = 'CalendarRow';
        objWrapper.appendChild(objFirstRow);
        var intCount = 0;
        for (intCount; intCount < dtmStart.getUTCDay(); intCount++)
        {
            var objNotThisMonth = document.createElement('div');
            objNotThisMonth.className = 'CalendarCell NotThisMonth';
            objFirstRow.appendChild(objNotThisMonth);
            objFirstRow.appendChild(document.createTextNode('\n'));
        }

        //Fill the rest of the first row with days
        for (intCount; intCount < 7; intCount++)
        {
            var objCalendarCell = document.createElement('div');
            objCalendarCell.className = 'CalendarCell';

            for (var j = 0; j < arrActiveDays.length; j++)
            {
                var dtmActiveDay = arrActiveDays[j];
                var blnIsActiveDay = dtmActiveDay.getTime() == dtmStart.getTime();
                var strLink = 'window.open(\'/?';
                strLink += blnIsActiveDay ? 'ci' : 'ci2';   // Choose the querystring parameter
                strLink += '=' + dtmActiveDay.getFullYear() + '-' + eval(dtmActiveDay.getMonth() + 1) + '-' + dtmActiveDay.getDate() + '\', \'_self\');'
                objCalendarCell.setAttribute('onclick', strLink);
                if (blnIsActiveDay)
                {
                    objCalendarCell.className += ' Active';
                }
            }

            if (dtmToday.getTime() == dtmStart.getTime())
            {
                if (dtmCurrent.getTime() == dtmStart.getTime())
                {
                    objCalendarCell.className += ' Today';
                }
                else
                {
                    objCalendarCell.className += ' TodayNotChosen';
                }
            }
            else if (dtmCurrent.getTime() == dtmStart.getTime())
            {
                objCalendarCell.className += ' Chosen';
            }

            objCalendarCell.appendChild(document.createTextNode(dtmStart.getDate()));
            objFirstRow.appendChild(objCalendarCell);
            objFirstRow.appendChild(document.createTextNode('\n'));
            dtmStart.setDate(dtmStart.getDate() + 1);
        }

        var objCalendarRow = document.createElement('div');
        objCalendarRow.className = 'CalendarRow';

        //Fill each row with days
        for (var i = dtmStart.getDate(); i <= intDaysInMonth; i++)
        {
            if (dtmStart.getUTCDay() == 0)
            {
                objWrapper.appendChild(document.createTextNode('\n'));
                objCalendarRow = document.createElement('div');
                objCalendarRow.className = 'CalendarRow';
                objWrapper.appendChild(objCalendarRow);
            }

            var objCalendarCell = document.createElement('div');
            objCalendarCell.className = 'CalendarCell';

            for (var j = 0; j < arrActiveDays.length; j++)
            {
                var dtmActiveDay = arrActiveDays[j];
                var blnIsActiveDay = dtmActiveDay.getTime() == dtmStart.getTime();
                var strLink = 'window.open(\'/?';
                strLink += blnIsActiveDay ? 'ci' : 'ci2';   // Choose the querystring parameter
                strLink += '=' + dtmActiveDay.getFullYear() + '-' + eval(dtmActiveDay.getMonth() + 1) + '-' + dtmActiveDay.getDate() + '\', \'_self\');'
                objCalendarCell.setAttribute('onclick', strLink);
                if (blnIsActiveDay)
                {
                    objCalendarCell.className += ' Active';
                }
            }

            if (dtmToday.getTime() == dtmStart.getTime())
            {
                if (dtmCurrent.getTime() == dtmStart.getTime())
                {
                    objCalendarCell.className += ' Today';
                }
                else
                {
                    objCalendarCell.className += ' TodayNotChosen';
                }
            }
            else if (dtmCurrent.getTime() == dtmStart.getTime())
            {
                objCalendarCell.className += ' Chosen';
            }

            objCalendarCell.appendChild(document.createTextNode(dtmStart.getDate()));
            objCalendarRow.appendChild(objCalendarCell);
            objCalendarRow.appendChild(document.createTextNode('\n'));

            dtmStart.setDate(dtmStart.getDate() + 1);
        }

        //Fill the rest of the last row with blank fields
        for (var i = dtmStart.getUTCDay(); i < 7; i++)
        {
            var objNotThisMonth = document.createElement('div');
            objNotThisMonth.className = 'CalendarCell NotThisMonth';
            objCalendarRow.appendChild(objNotThisMonth);
            objCalendarRow.appendChild(document.createTextNode('\n'));
        }

    }

    this.viewMonths = function (dtmStart)
    {
        dtmStart = new Date(dtmStart);
        if (dtmStart.getDate() > 1)
            dtmStart.setDate(1);

        for (var i = objWrapper.childNodes.length; i >= 0; i--)
        {
            var objChild = objWrapper.childNodes[i];
            if (objChild)
            {
                if (objChild.className != 'CalendarRowNavi')
                {
                    objWrapper.removeChild(objChild);
                }
            }
        }

        //Set the correct text and link on the top field
        while (objCalendarYear.hasChildNodes())
        {
            objCalendarYear.removeChild(objCalendarYear.firstChild);
        }
        objCalendarYear.appendChild(document.createTextNode(dtmStart.getFullYear()));
        objCalendarYear.setAttribute('onclick', strVarName + '.viewYears(\'' + new Date(dtmStart.getFullYear(), 0, 1) + '\')');
        //Do the same for the navigation buttons
        objNaviLeft.setAttribute('onclick', strVarName + '.viewMonths(\'' + new Date(dtmStart.getFullYear() - 1, dtmStart.getMonth(), 1) + '\')');
        objNaviRight.setAttribute('onclick', strVarName + '.viewMonths(\'' + new Date(dtmStart.getFullYear() + 1, dtmStart.getMonth(), 1) + '\')');

        var objCalendarMonthRow = null;

        for (var i = 0; i < arrMonths.length; i++)
        {
            if (i % 3 == 0)
            {
                objCalendarMonthRow = document.createElement('div');
                objCalendarMonthRow.className = 'CalendarMonthRow';
                objWrapper.appendChild(objCalendarMonthRow);
            }

            var objCalendarCell = document.createElement('div');
            objCalendarCell.className = 'CalendarCell';
            objCalendarCell.appendChild(document.createTextNode(arrMonths[i]));
            objCalendarCell.appendChild(document.createTextNode('\n'));
            objCalendarCell.setAttribute('onclick', strVarName + '.viewDays(\'' + new Date(dtmStart.getFullYear(), i, 1) + '\')');
            objCalendarMonthRow.appendChild(objCalendarCell);
            objCalendarMonthRow.appendChild(document.createTextNode('\n'));
        }
    }

    this.viewYears = function (dtmStart)
    {
        dtmStart = new Date(dtmStart);
        if (dtmStart.getDate() > 1)
            dtmStart.setDate(1);

        for (var i = objWrapper.childNodes.length; i >= 0; i--)
        {
            var objChild = objWrapper.childNodes[i];
            if (objChild)
            {
                if (objChild.className != 'CalendarRowNavi')
                {
                    objWrapper.removeChild(objChild);
                }
            }
        }

        //Set the correct text and link on the top field
        while (objCalendarYear.hasChildNodes())
        {
            objCalendarYear.removeChild(objCalendarYear.firstChild);
        }
        objCalendarYear.appendChild(document.createTextNode(dtmStart.getFullYear() + ' - ' + eval(dtmStart.getFullYear() + 11)));
        //Do the same for the navigation buttons
        objNaviLeft.setAttribute('onclick', strVarName + '.viewYears(\'' + new Date(dtmStart.getFullYear() - 12, 0, 1) + '\')');
        objNaviRight.setAttribute('onclick', strVarName + '.viewYears(\'' + new Date(dtmStart.getFullYear() + 12, 0, 1) + '\')');

        var objCalendarYearRow = null;

        for (var i = 0; i < 12; i++)
        {
            if (i % 3 == 0)
            {
                objCalendarYearRow = document.createElement('div');
                objCalendarYearRow.className = 'CalendarYearRow';
                objWrapper.appendChild(objCalendarYearRow);
            }

            var objCalendarCell = document.createElement('div');
            objCalendarCell.className = 'CalendarCell';
            objCalendarCell.appendChild(document.createTextNode(eval(dtmStart.getFullYear() + i)));
            objCalendarCell.appendChild(document.createTextNode('\n'));
            objCalendarCell.setAttribute('onclick', strVarName + '.viewMonths(\'' + new Date(eval(dtmStart.getFullYear() + i), 0, 1) + '\')');
            objCalendarYearRow.appendChild(objCalendarCell);
            objCalendarYearRow.appendChild(document.createTextNode('\n'));
        }
    }

    this.addActiveDay = function (inDate)
    {
        arrActiveDays[arrActiveDays.length] = inDate;
    }

    CreateHeader = function (inType)
    {
        var objHeader = document.createElement('div');
        objHeader.className = 'Header';

        var objHeaderImage = document.createElement('img');
        objHeaderImage.src = '/gfx/box/headers/calendar.png';
        objHeaderImage.width = '16';
        objHeaderImage.width = '151';
        objHeaderImage.alt = 'Maritim Kalender';
        objHeader.appendChild(objHeaderImage);

        var objContent = document.createElement('div');
        objContent.className = 'Content';

        objWrapper = document.createElement('div');
        objWrapper.className = 'CalendarWrapper';
        objContent.appendChild(objWrapper);

        var objCalendarRowNavi = document.createElement('div');
        objCalendarRowNavi.className = 'CalendarRowNavi';
        objWrapper.appendChild(objCalendarRowNavi);
        objCalendarRowNavi.appendChild(document.createTextNode('\n'));

        objNaviLeft = document.createElement('div');
        objNaviLeft.className = 'CalendarCell NaviLeft';
        objCalendarRowNavi.appendChild(objNaviLeft);
        objCalendarRowNavi.appendChild(document.createTextNode('\n'));

        objCalendarYear = document.createElement('div');
        objCalendarYear.className = 'CalendarCell CalendarYear';
        objCalendarRowNavi.appendChild(objCalendarYear);
        objCalendarRowNavi.appendChild(document.createTextNode('\n'));

        objNaviRight = document.createElement('div');
        objNaviRight.className = 'CalendarCell NaviRight';
        objCalendarRowNavi.appendChild(objNaviRight);

        while (objBoxCalendar.hasChildNodes())
        {
            objBoxCalendar.removeChild(objBoxCalendar.firstChild);
        }
        objBoxCalendar.appendChild(objHeader);
        objBoxCalendar.appendChild(objContent);
    }

    DaysInMonth = function (year, month)
    {
        return 32 - new Date(year, month, 32).getDate();
    }
}