Open a PDF file using VB.NET in an UpdatePanel

After hours of trying n searching, i finally got it done by the following way:
Use a trigger for UpdatePanel on the button
Register your client side script in the button click even
Sample Code:

(ASCX)
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<triggers>
<asp:postbacktrigger controlid="btnSubmit" />
</triggers>
<ContentTemplate>
(ASCX.CS)
Dim strscriptMF As String
strscriptMF = "<script language=javascript>window.open('" & pdfPathMF & "')</script>"
Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), "strScriptMF", strscriptMF)

Reference:

http://forums.asp.net/p/1082431/1605489.aspx#1605489