$(document).ready(function() {
		
		$("#nav img").each(function() {
			rollsrc = $(this).attr("src");
			rollON = rollsrc.replace(/.jpg$/ig,"_over.jpg");
			$("<img>").attr("src", rollON);
		});
		
		$("#nav a").mouseover(function(){
			imgsrc = $(this).children("img").attr("src");
			matches = imgsrc.match(/_over/);
			
			if (!matches) {
			imgsrcON = imgsrc.replace(/.jpg$/ig,"_over.jpg");
			$(this).children("img").attr("src", imgsrcON);
			}
			
		});
		$("#nav a").mouseout(function(){
			$(this).children("img").attr("src", imgsrc);
		});
		
	});