Add try this code .. Its working grt.......
<body>_x000D_
<?php_x000D_
if (isset($_POST['nav'])) {_x000D_
header("Location: $_POST[nav]");_x000D_
}_x000D_
?>_x000D_
<form id="page-changer" action="" method="post">_x000D_
<select name="nav">_x000D_
<option value="">Go to page...</option>_x000D_
<option value="http://css-tricks.com/">CSS-Tricks</option>_x000D_
<option value="http://digwp.com/">Digging Into WordPress</option>_x000D_
<option value="http://quotesondesign.com/">Quotes on Design</option>_x000D_
</select>_x000D_
<input type="submit" value="Go" id="submit" />_x000D_
</form>_x000D_
</body>_x000D_
</html>
_x000D_
<html>_x000D_
<head>_x000D_
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>_x000D_
<script>_x000D_
$(function() {_x000D_
_x000D_
$("#submit").hide();_x000D_
_x000D_
$("#page-changer select").change(function() {_x000D_
window.location = $("#page-changer select option:selected").val();_x000D_
})_x000D_
_x000D_
});_x000D_
</script>_x000D_
</head>
_x000D_