<html>
<body>
<script>
function whatisx()
{
var x = "a string";
return "Surprise!: X is " + whatisx();
function whatisx()
{
var x = 99;
return(x);
}
}
</script>
<div id"x" onclick="alert(whatisx());" style="background:red; color:white;">Click to find out what X is</div>
</body>
</html>