You need to use OnLoad event handler of JavaScript Image object.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
</head>
<body>
<script type="text/javascript">
PreloadImages();
function PreloadImages() {
var images = new Array();
images.push("http://static.flickr.com/66/199481236_dc98b5abb3_s.jpg");
images.push("http://static.flickr.com/75/199481072_b4a0d09597_s.jpg");
images.push("http://static.flickr.com/57/199481087_33ae73a8de_s.jpg");
for (var i = 0; i < images.length; i++) {
var image = new Image();
image.src = images[i];
image.onload = function () {
var img = document.createElement("IMG");
img.src = this.src;
document.getElementById("dvImages").appendChild(img);
};
}
};
</script>
<div id="dvImages">
</div>
</body>
</html>
Demo