js控制table表的列排序
<script src="sorttable.js"></script>
<table class="sortable">
<thead>
  <tr><th>Person</th><th>Monthly pay</th></tr>
</thead>
<tbody>
  <tr><td>Jan Molby</td><td>1</td></tr>
  <tr><td>Steve Nicol</td><td>3</td></tr>
  <tr><td>Steve McMahon</td><td>2</td></tr>
  <tr><td>John Barnes</td><td>4</td></tr>
</tbody>
<tfoot>
  <tr><td>TOTAL</td><td>10</td></tr>
</tfoot>
</table>

sorttable.js

/*
  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].classNa