var funChangeImg = function(strImage) {
	
	var arrHoverSrc = []
	
	// loop through all the elements with the class img_lnk
	$ES('img.img_link').each(function(eleImgLink, intIndex) {
		// extract the property 'src'
		strSrc = eleImgLink.getProperty('src');
		
		// construct the name of the file with _hover appened onto it
		arrHoverSrc[intIndex] = strSrc.substr(0, strSrc.length - 4)+'_hover.gif';
		strHoverSrc = arrHoverSrc[intIndex];
		
		// change the element's src property on mouseover
		eleImgLink.addEvent('mouseenter', function(strHoverSrc) {
			this.setProperty('src', strHoverSrc);
			this.addClass('img_link_hover');
		}.pass(strHoverSrc, eleImgLink));
		
		// change it back on mouseout
		eleImgLink.addEvent('mouseleave', function(strSrc) {
			this.setProperty('src', strSrc);
			this.removeClass('img_link_hover');
		}.pass(strSrc, eleImgLink));
	});
	
	// precache the hover state images
	new Asset.images(arrHoverSrc);
}

window.addEvent('domready', function() {
	funChangeImg();
});