Open PDF File In Asp.net C#

foreach (GridViewRow gr in GridViewTnf.Rows)
{
    HyperLink hp = new HyperLink();
    hp.Text = gr.Cells[1].Text;
    hp.NavigateUrl = "DownloadFile.aspx?Name="+hp.Text+".pdf";
    gr.Cells[1].Controls.Add(hp);
    Page.Controls.Add(new LiteralControl("<br/>"));
}