JavaScript DHTML/Event onMethod/onBounce
"onBounce" Example
<head>
<script language="JavaScript">
function function1() {
alert("The marquee content reached one of its edges")
}
</script>
</head>
<body>
<marquee width=500
behavior="alternate"
onbounce="function1()"
bgcolor="#EEEEEE">marquee</marquee>
</body>