show open/save dialog for pdf documents in c# application

I have a link button and whe user clicks on it , I want to open/save dialogue screen to come up to allow user to either save or open the pdf document. Here is my code below. It is just opening the pdf document. Pls assist.

protected void lnkOpenPdf_Click(object sender, EventArgs e)
        WebClient client = new WebClient();
        string studentNumber;
        studentNumber = User.Identity.Name;
        string pdfPath = Server.MapPath("./store/" + studentNumber + ".pdf");
        Byte[] buffer = client.DownloadData(pdfPath);
        Response.ContentType = "application/pdf";
        Response.AddHeader("Content-Disposition", buffer.Length.ToString());

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Edgard YamashitaSystems AnalystCommented:
try like this:

Response.ContentType = "application/pdf";

Response.AppendHeader("Content-Disposition","attachment; filename=mypdf.pdf");

Response.TransmitFile( Server.MapPath("./store/" + studentNumber + ".pdf") );


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SirdotsAuthor Commented:
Thanks. It works like Magic.
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