$(document).ready(function() {
 			$("#nav img.m1").each(function() {
 				rollsrc = $(this).attr("src");
				rollON = rollsrc.replace(/.jpg$/ig,"_over.jpg");
				$("<img>").attr("src", rollON);
			});
		
	 		$("#nav a.m1").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.m1").mouseout(function(){
				$(this).children("img").attr("src", imgsrc);
			});
		});