<html>
<head>
<title> </title>
<script>
function openWin()
{ window.open("http://www.baidu.com");
}
</script>
</head>
<body>
<select name = "selM" onchange="openWin()">
<option value = "1">1 </option>
<option value = "2">2 </option>
</select>
</body>
</html>
<head>
</head>
<script type="text/javascript">
function select() {
window.open();
}
</script>
<body>
<select id="Select1" onchange="select()">
<option selected="selected">1</option>
<option >2</option>
</select>
</body>
</html>