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 a = new Array();
 	for (var i=0; i<trs.length; i++) {
  		a[i] = trs[i];
 	}
 	a.sort(compareByColumn(nCol,bDesc,sType));
 	for (var i=0; i<a.length; i++) {
  		tBody.appendChild(a[i]);
 	}
}
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 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;
 	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 sortColumn(e) {
 	var tmp, el, tHeadParent;
 	if (ie5){
  		tmp = e.srcElement;
 	}
 	else if (dom){
  		tmp = e.target;
 	}
 	tHeadParent = getParent(tmp, "THEAD");
 	el = getParent(tmp, "TD");
 	if (tHeadParent == null){
  		return;
  	}
 	if (el != null) {
  		var p = el.parentNode;
  		var i;
  		if (el._descending){
  			 // catch the null
   			el._descending = false;
  		}
  		else{
   			el._descending = true;
  		}
  		if (tHeadParent.arrow != null) {
   			if (tHeadParent.arrow.parentNode != el) {
    			tHeadParent.arrow.parentNode._descending = null;   
   			}
   			tHeadParent.arrow.parentNode.removeChild(tHeadParent.arrow);
  		}
  		if (el._descending){
   			tHeadParent.arrow = arrowDown.cloneNode(true);
  		}
  		else{
   			tHeadParent.arrow = arrowUp.cloneNode(true);
  		}
  		el.appendChild(tHeadParent.arrow);
  		// get the index of the td
  		for (i=0; i<p.cells.length; i++) {
   			if (p.cells[i] == el) break;
  		}
  		var table = getParent(el, "TABLE");
  		// can't fail
  		sortTable(table,i,el._descending, el.getAttribute("type"));
 	}
}

function getInnerText(el) {
 	if (ie5){
 		 return el.innerText; //Not needed but it is faster
 	}
 	var str = "";
 
 	for (var i=0; i<el.childNodes.length; i++) {
  		switch (el.childNodes.item(i).nodeType) {
   			case 1: //ELEMENT_NODE
    			str += getInnerText(el.childNodes.item(i));
    			break;
   			case 3: //TEXT_NODE
    			str += el.childNodes.item(i).nodeValue;
    			break;
  		}
 	}
 	return str;
}
function getParent(el, pTagName) {
 	if (el == null){
 		return null;
 	}
 	else if (el.nodeType == 1 && el.tagName.toLowerCase() == pTagName.toLowerCase()){
  		return el;
  	}
 	else{
  		return getParent(el.parentNode, pTagName);
  	}
}