Event.observe(window,"load",function(){var B="";if(null==(B=Cookie.get("bg"))){B=BGs[$random(0,BGs.length-1)];Cookie.set("bg",B,0)}$E("body").setStyle({backgroundImage:"url("+B+")"})});function clearbg(){Cookie.erase("bg");if(null!=Cookie.get("bg")){alert("remove failed")}};