Asp.net file upload control using ajax(update panel)

Today i want to show file upload control using ajax

here is .aspx

<asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">

</asp:ToolkitScriptManager>

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

<asp:PostBackTrigger ControlID="Button1"/>

</Triggers>

<asp:FileUpload ID="FileUpload1" runat="server" />

<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />

</ContentTemplate>

</asp:UpdatePanel>

And at .cs page you can get like below.

protected void Button1_Click(object sender, EventArgs e)

{

string a = FileUpload1.PostedFile.FileName;

}