eskimoblueday,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
</head>
<body>
<input type="text" class="test">
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script type="text/javascript">
$(".test").keyup(function( ){
var val = $(this).val()
$(this).css({color:/http/.test(val)?'red':''})
});
</script>
</body>
</html>