The pageYOffSet property reflects the current vertical pixel location of the top-left corner of the document.
<html>
<head>
<script language="JavaScript1.2">
<!--
function showLocation(){
var x = self.pageXOffset;
var y = self.pageYOffset
var currX = "X-coordinate: " + x + "\n";
var currY = "Y-coordinate: " + y;
window.alert(currX + currY);
}
-->
</script>
</head>
<body>
<form>
<input type=BUTTON value="Show Location" onClick="showLocation()">
</form>
</body>
</html>