获取屏幕分辨率

var aa=window.screen.width;
switch (aa) {
 case 1366:$(".img1").attr({"data-x":-550,"date-y":0}); 
  //$(".img1 img").attr("width",200);
break;
 case 30: alert("30");
break;
 case 40: alert("40");
break;
 default: alert("other");
}