JavaScript实现表格排序

<script language="javascript">   
    var dom = (document.getelementsbytagname) ? true : false;   
    var ie5 = (document.getelementsbytagname && document.all) ? true : false;   
    var arrowup, arrowdown;   
    if (ie5 || dom)   
        initsorttable();   
    function initsorttable() {   
        arrowup = document.createelement("span");   
        var tn = document.createtextnode("↑");   
        arrowup.appendchild(tn);   
        arrowup.classname = "arrow";   
        arrowdown = document.createelement("span");   
        var tn = document.createtextnode("↓");   
        arrowdown.appendchild(tn);   
        arrowdown.classname = "arrow";   
    }   
    function sorttable(tablenode, ncol, bdesc, stype) {   
        var tbody = tablenode.tbodies[0];   
        var trs = tbody.rows;   
        var trl= trs.length;   
        var a = new array();   
        for (var i = 0; i < trl; i++) {   
            a[i] = trs[i];   
        }   
        var start = new date;   
        window.status = "sorting data...";   
        a.sort(comparebycolumn(ncol,bdesc,stype));   
        window.status = "sorting data done";   
        for (var i = 0; i < trl; i++) {   
            tbody.appendchild(a[i]);   
            window.status = "updating row " + (i + 1) + " of " + trl +   
                " (time spent: " + (new date - start) + "ms)";   
        }   
        // check for onsort   
        if (typeof tablenode.onsort == "string")   
            tablenode.onsort = new function("", tablenode.onsort);   
        if (typeof tablenode.onsort == "function")   
            tablenode.onsort();   
    }   
    function caseinsensitivestring(s) {   
        return string(s).touppercase();   
    }   
    function parsedate(s) {   
        return date.parse(s.replace(/-/g, /));   
    }   
    function tonumber(s) {   
        return number(s.replace(/[^0-9.]/g, ""));   
    }   
    function percent(s) {   
        return number(s.replace("%", ""));   
    }   
    function comparebycolumn(ncol, bdescending, stype) {   
        var c = ncol;   
        var d = bdescending;   
        var ftypecast = string;   
        if (stype == "number")   
            ftypecast = number;   
        else if (stype == "date")   
            ftypecast = parsedate;   
        else if (stype == "caseinsensitivestring")   
            ftypecast = caseinsensitivestring;   
        else if (stype == "percent")   
            ftypecast = percent;   
        return function (n1, n2) {   
            if (ftypecast(getinnertext(n1.cells[c])) < ftypecast(getinnertext(n2.cells[c])))   
                return d ? -1 : +1;   
            if (ftypecast(getinnertext(n1.cells[c])) > ftypecast(getinnertext(n2.cells[c])))   
                return d ? +1 : -1;   
            return 0;   
        };   
    }   
    function sortcolumnwithhold(e) {   
        var el = ie5 ? e.srcelement : e.target;   
        var table = getparent(el, "table");   
        var oldcursor = table.style.cursor;   
        var oldclick = table.onclick;   
        table.style.cursor = "wait";   
        table.onclick = null;   
        var fakeevent = {srcelement : e.srcelement, target : e.target};   
        window.settimeout(function () {   
            sortcolumn(fakeevent);   
            table.style.cursor = oldcursor;   
            table.onclick = oldclick;   
        }, 100);   
    }   
    function sortcolumn(e) {   
        var tmp = e.target ? e.target : e.srcelement;   
        var theadparent = getparent(tmp, "thead");   
        var el = getparent(tmp, "td");   
        if (theadparent == null)