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("5");
	arrowUp.appendChild(tn);
	arrowUp.className = "arrow";


	arrowDown = document.createElement("SPAN");
	var tn = document.createTextNode("6");
	arrowDown.appendChild(tn);
	arrowDown.className = "arrow";
}






function sortTable(tableNode, nCol, bDesc) {
	var tBody = tableNode.tBodies[0];
	var trs = tBody.childNodes;
	var a = new Array();
	
	for (var i=0; i<trs.length; i++) {
		a[i] = trs[i];
	}
	
	a.sort(compareByColumn(nCol,bDesc));
	
	for (var i=0; i<a.length; i++) {
		tBody.appendChild(a[i]);
	}
}


function compareByColumn(nCol, bDescending) {
	var c = nCol;
	var d = bDescending;


	function _compare(n1, n2) {
		var v;
		if (getInnerText(n1.cells[c]) < getInnerText(n2.cells[c]))
			v = (d) ? -1 : +1;
		else if (getInnerText(n1.cells[c]) > getInnerText(n2.cells[c]))
			v = (d) ? +1 : -1;
		else 
			v = 0;
//		alert("n1: " + getInnerText(n1.cells[c]) + "\nn2: " + getInnerText(n2.cells[c]) + "\nv: " + v);


		return v;
	}
	
	return _compare;
}




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;	//reset sort order		
			}
			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.childNodes.length; i++) {
			if (p.childNodes[i] == el) break;
		}


		var table = getParent(el, "TABLE");
		// can't fail
		
		sortTable(table,i,el._descending);
	}
}




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())	// Gecko bug, supposed to be uppercase
		return el;
	else
		return getParent(el.parentNode, pTagName);
}