SO fiddle
Test Fiddle mainly for SO Questions
by Nick Craver
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<script type="text/javascript">
function SanitizeInput(input) {
input = input.replace(/</g, "<");
input = input.replace(/>/g, ">");
return input;
}
document.write(SanitizeInput("Test!<marquee>bibble</marquee>"));
</script>