how to display OPEN FILE DIALOG on LINKBUTTON click

    <script type="text/javascript">
        function displayOpenFileDialog()
         {
            document.getElementById("FileUpload1").click();
         }
    </script>


<asp:FileUpload ID="FileUpload1" runat="server" style="display:none" />
        <asp:LinkButton ID="LinkButton1" runat="server" OnClientClick="JavaScript:displayOpenFileDialog()">LinkButton</asp:LinkButton>