function executeRollovers(){
	var allLinksArray = document.getElementsByTagName('a');
	var rollovers = new Array();
	var count=0;
	
	for(var i=0; i<allLinksArray.length; i++){
		var thisClass = allLinksArray[i].className;
		if(thisClass.indexOf('rollover') != -1){
			rollovers[count]= allLinksArray[i];
			count++;
		}
	}
	//console.info(rollovers.length);
	for(var i = 0; i<rollovers.length; i++){
		var rolloverImg = rollovers[i].getElementsByTagName('img')[0];
		var rolloverSrc = rolloverImg.getAttribute('src');
		preloadImage(rolloverSrc);
		rollovers[i].onmouseover = function(){
			var thisImg = this.getElementsByTagName('img')[0];
			var oldSrc= thisImg.getAttribute('src');
			//alert(oldSrc);
			var newSrc = oldSrc.replace(/\.gif/, '_o.gif');
			//newSrc = oldSrc.replace(/\.jpg/, '_o.jpg');
			thisImg.setAttribute('src', newSrc);
			//console.info('success');
		}
		rollovers[i].onmouseout = function(){
			var thisImg = this.getElementsByTagName('img')[0];
			var oldSrc= thisImg.getAttribute('src');
			var newSrc = oldSrc.replace(/_o\./, '.');
			thisImg.setAttribute('src', newSrc);
		}
	}
	function preloadImage(src){
		var preloader= new Image();
		preloader.src = src;
		//console.info('loaded');
	}
}
//always check to see if the addLoadEvent function exists before trying to call it!
if(typeof addEventListener == 'function'){
	addEventListener(executeRollovers);
}

// adds functions to the window.onload event
function addEventListener(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func;
    }
  }
};