var ist_gNavRollover = new Object();
ist_gNavRollover = {initRollovers : function() {
		if (!document.getElementById) return
		var aPreLoad = new Array();
		var aImages = document.getElementsByTagName('img');
		for (var i = 0; i < aImages.length; i++) {
			if (aImages[i].className == 'gNavOver') {
				var src = aImages[i].getAttribute('src');
				var ftype = src.substring(src.lastIndexOf('.'), src.length);
				var hsrc = src.replace(ftype, '_o' + ftype);
				aImages[i].setAttribute('hsrc', hsrc);
				aImages[i].setAttribute('osrc', src);
				aPreLoad[i] = new Image();
				aPreLoad[i].src = hsrc;
				
				aImages[i].onmouseover = function() {
					this.setAttribute('src', this.getAttribute('hsrc'));
				}
				aImages[i].onmouseout = function() {
					this.setAttribute('src', this.getAttribute('osrc'));
				}
			}
		}
	}
}

try{
	window.addEventListener('load', ist_gNavRollover.initRollovers, false);
} catch(e){
	window.attachEvent('onload', ist_gNavRollover.initRollovers);
}