CSCI 4230
Internet Applicaiton Development
Fall 2000
Suugested Solution to Homework #7

(1)    For example:

<html>
<head>
<script>
function updateClip() {
    if (document.layers) {
  var clipper = document.layers["uhcl"];
  clipper.visibility = "visible";
  clipper.clip.width = im.width * (curr+1) / UPDATE_STEP;
  clipper.clip.height = im.height * (curr+1) / UPDATE_STEP;
 }
 else if (document.all) {
  var clipper = document.all["uhcl"];
  clipper.style.visibility = "visible";
  clipper.style.clip = "rect(0 " + (im.width * (curr+1) / UPDATE_STEP) + " " + (im.height * (curr+1) / UPDATE_STEP) + " 0)";
 }

 curr++;
 if (curr < UPDATE_STEP) {
  setTimeout("updateClip()", UPDATE_PERIOD);
 }
    return;
 
}

var UPDATE_PERIOD = 40;
var UPDATE_STEP = 40;

var curr = 0;
var im = new Image();

function startup() {
    im.src = "UHCLBanner.gif";
    updateClip();
}
</script>
</head>
<body bgcolor="#ccccff" onLoad="startup()">
<div id="uhcl" style="position:absolute;visibility:hidden">
<img name="uhclimage" src="UHCLBanner.gif">
</div>
</body>
</html>