JS控制不准粘贴

JS控制不准粘贴

<script>
       //禁止粘贴文本框
        function fncKeyStop(evt)
        {
            if(!window.event)
            {
                var keycode = evt.keyCode;
                var key = String.fromCharCode(keycode).toLowerCase();
                if(evt.ctrlKey && key == "v")
                {
                   evt.preventDefault();
                   evt.stopPropagation();
                }
                if(evt.ctrlKey && key == "x")
                {
                   evt.preventDefault();
                   evt.stopPropagation();
                }
            }
        }
</script>

控件代码（文本框）：
<asp:TextBox ID="txt_orderNo_confirm" runat="server" οnkeydοwn="fncKeyStop(event)" οnpaste="return false" oncontextmenu = "return false;"></asp:TextBox>