js 获取Listbox选择的值的代码

<script type="text/javascript"> 
function GetValue() { 
var strlist = document.getElementById("ListBox1");//获取Listbox 
var str= ""; 
//遍历Listbox，取得选中项的值 
if (strlist.options.length > 0) { 
for (var i = 0; i < strlist.options.length; i++) { 
if (strlist.options[i].selected == true) { 
var j = strlist.options[i].value; 
str+=j+","; //把Value值串起来
} 
} 
var strValue=str.replace(/,$/, ""); //去掉最后一个逗号 
alert(strValue); 
} 
else { 
alert("No Item in Listbox"); 
} 
} 
</script>