// JavaScript Document
var rO = {
	addEvent: function(elm, evType, fn, useCapture) {
		if (elm.addEventListener) {
		  elm.addEventListener(evType, fn, useCapture);
		  return true;
		} else if (elm.attachEvent) {
		  var r = elm.attachEvent('on' + evType, fn);
		  return r;
		} else {
		  elm['on' + evType] = fn;
		}
	},
	setupRollovers: function() {
	  if (!document.getElementsByTagName)
		return;
	  var leftnav = document.getElementById("main_nav");	
	  var all_links = leftnav.getElementsByTagName('a');
	  for (var i = 0; i < all_links.length; i++) {
		var link = all_links[i]; 
		  if (link.childNodes && link.childNodes.length == 1 && link.childNodes[0].nodeName.toLowerCase() == 'img') {
			if(link.childNodes[0].src.indexOf('_over') == -1){
				rO.addEvent(link,"mouseover",rO.mouseover,false);
				rO.addEvent(link,"mouseout",rO.mouseout,false);
			}
		  }
	  }
	},
	find_target: function(e){
	  /* Begin the DOM events part, which you */
	  /* can ignore for now if it's confusing */
	  var target; 
	
	  if (window.event && window.event.srcElement) 
		target = window.event.srcElement;
	  else if (e && e.target)
		target = e.target;
	  if (!target)
		return null;
	
	  while (target != document.body &&
		  target.nodeName.toLowerCase() != 'a')
		target = target.parentNode;
	
	  if (target.nodeName.toLowerCase() != 'a')
		return null;
	
	  return target;
	},
	
	
	mouseover: function(e) {
	  var target = rO.find_target(e);
	  if (!target) return;
	
	  // the only child node of the a tag in target will be an img tag
	  var img_tag = target.childNodes[0];
	
	  // Take the "src", which names an image called "something.ext",
	  // Make it point to "something_over.ext"
	  // This is done with a regular expression
	  	img_tag.src = img_tag.src.replace(/(\.[^.]+)$/, '_over$1');
	},
	
	mouseout: function(e) {
	  var target = rO.find_target(e);
	  if (!target) return;
	
	  // the only child node of the A-tag in |target| will be an IMG-tag
	  var img_tag = target.childNodes[0];
	
	  // Take the "src", which names an image as "something_over.ext",
	  // Make it point to "something.ext"
	  // This is done with a regular expression
	  img_tag.src = img_tag.src.replace(/_over(\.[^.]+)$/, '$1');
	},
	repositionFooter: function(){
		if(document.getElementById("footer")){
			footer = document.getElementById("footer");
			footer.style.position = "absolute";
			footer.style.bottom = 0;
		}
	},
	init: function(){
		
		rO.setupRollovers();
		
		rO.repositionFooter();
		
	}	
}
rO.addEvent(window,"load",rO.init,false);