e621 swimmer updated

// ==UserScript==
// @name             E621 Swimmer
// @description      Navigate e621's pools with arrow keys
// @include          http*://e621.net/post/show/*
// ==/UserScript==
window.onLoad = checkForPool();
function checkForPool()
{
    var tags = document.getElementsByTagName('h6');
    for (var i = 0; i < tags.length; ++i)
    {
        if (tags[i].innerHTML === 'Pool')
        {
            var parent = tags[i].parentNode;
            var innerTags = parent.getElementsByTagName('a');
            document.addEventListener('keydown', function (e)
            {
                //Uncomment any of these if some modifier key is wanted,
                // uncommenting all three will require all three to be pressed
                //if (!e.shiftKey){ return; }
                //if (!e.ctrlKey){ return; }
                //if (!e.metaKey){ return; }

                //Return if target is a text field (where text navigation takes precedence)
                var t = e.srcElement || e.target;
                var tagName = t.tagName.toUpperCase();
                var type = '';
                if (t.type){
                    type = t.type.toUpperCase();
                }
                if ((tagName === 'INPUT' &&
                     (
                    type === 'TEXT' ||
                    type === 'PASSWORD' ||
                    type === 'SEARCH' ||
                    type === 'EMAIL' ||
                    type === 'NUMBER' ||
                    type === 'DATE' )
                     ) ||
                    tagName === 'TEXTAREA')
                {
                    return;
                }

                var p = innerTags[1];
                var n = p;
                if (innerTags.length > 2){
                    n = innerTags[2];
                }
                if (e.keyCode === 37 && p.innerHTML.substring(0, 8) == "&lt;&lt;")
                {
                    window.location=p.href;
                }
                else if (e.keyCode === 39 && n.innerHTML.substring(n.innerHTML.length-8, n.innerHTML.length) == "&gt;&gt;")
                {
                    window.location=n.href;
                }
            }, false);
            break;
        }
    }
}