<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>

js 操作Listbox

function SelectAll()
        {
            var lst1=window.document.getElementById("SourceListBox");
            var length = lst1.options.length;
            for(var i=0;i            {
                var v = lst1.options[i].value;
                var t = lst1.options[i].text;
                var lst2=window.document.getElementById("DestinationListBox");
                lst2.options[i] = new Option(t,v,true,true);   
            }
           
        }
       
        function DelAll()
        {
            var lst2=window.document.getElementById("DestinationListBox");
            var length = lst2.options.length;
            for(var i=length;i>0;i--)
            {
                lst2.options[i-1].parentNode.removeChild(lst2.options[i-1]);
            }   
        }
       
        function SelectOne()
        {
            var lst1=window.document.getElementById("SourceListBox");
            var lstindex=lst1.selectedIndex;
            if(lstindex<0)
                return;
            var v = lst1.options[lstindex].value;
            var t = lst1.options[lstindex].text;
            var lst2=window.document.getElementById("DestinationListBox");
            lst2.options[lst2.options.length] = new Option(t,v,true,true);   
               
        }
       
        function DelOne()
        {
            var lst2=window.document.getElementById("DestinationListBox");
            var lstindex=lst2.selectedIndex;
            if(lstindex>=0)
            {
                var v = lst2.options[lstindex].value+";";
                lst2.options[lstindex].parentNode.removeChild(lst2.options[lstindex]);
            }
               
        }