$(document).ready(function(){
		$("#bannerlist img")
			.bind("mouseover",function(){
				this.src = this.src.replace(/^(.+)_off(\.[a-z]+)$/, "$1_on$2");
			})
			.bind("mouseout",function(){
				this.src = this.src.replace(/^(.+)_on(\.[a-z]+)$/, "$1_off$2");
			});
		});