open image in browser fit to screen with window open

1$(".view-full-size").click(function() {
2
3  var mainScreenshot = $("#main-screenshot");
4	
5  var theImage = new Image();
6  theImage.src = mainScreenshot.attr("src");
7	
8  var winWidth = theImage.width + 20;
9  var winHeight = theImage.height + 20;
10	
11  window.open(this.href,  null, 'height=' + winHeight + ', width=' + winWidth + ', toolbar=0, location=0, status=0, scrollbars=0, resizable=0'); 
12	
13  return false;
14	
15});