<head runat="server">
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<script type="text/javascript" src="js/jquery-1.11.1.min.js"></script>
<title>無標題頁</title>
</head>
<script type="text/javascript">
function SELECT(index){
var select = document.getElementById("Select1");
select.selectedIndex=index;
}
$(document).ready(function () {
SELECT(1);
});
</script>
<body>
<form id="form1" runat="server">
<select id="Select1">
<option value="0">否</option>
<option value="1">是</option>
</select>
<div></div>
</form>
</body>
參考源碼：