怎么在javascript实现Button1.Enabled=true
function test(obj)
{
var tmp = obj.options[obj.selectedIndex].innerText;
document.getElementById("Text1").value = tmp + "<<";
document.all.Button1.Enabled ="true";
}
</script>
<SELECT id="ListBox2" ondblclick="test(this);" style="WIDTH: 180px; HEIGHT: 168px" size="10" name="ListBox2" runat="server">
Button1.Enabled始终为False
请各位大哥帮一帮忙