如何在客户端对Web DropDownList控件清空（clear）?

Question

如何在客户端清空Web DropDownList控件（clear）?

Answer 1

javascript
this.dropdownlist1.options.lengh=0;

Answer 2

ddlcbrand=document.getElementById("ddlcbrand");
       for(var i=ddlcbrand.length-1;i>=0;i--)
                 {
                   ddlcbrand.remove(i);
                 }

Answer 3

假如Web DropDownList的id为XXX：
<script language="javascript">
var obj = document.getElementById("XXX");for (i = obj.options.length; i >= 0 ; i--)
{
    obj.options.remove(i);
}
</script>

Answer 4

假如Web DropDownList的id为XXX：
<script language="javascript">
var obj = document.getElementById("XXX");for (i = obj.options.length - 1; i >= 0 ; i--)
{
    obj.options.remove(i);
}
</script>

Answer 5

document.all.DropDownList1.options.length=0;
DropDownList1为ID