ASP.NET

protected void uploadFile()<br />
    {<br />
        String projectID = (String)Session["projId"];<br />
        //change the file name<br />
        if (!FileUpload.FileName.Equals(""))<br />
        {<br />
            String fileName = FileUpload.FileName.Replace(FileUpload.FileName, "myDesiredFileName");<br />
            String extension = FileUpload.FileName.Substring(FileUpload.FileName.LastIndexOf("."));<br />
            // Create a new folder in Docs folder (folder name = projectID)<br />
            System.IO.Directory.CreateDirectory(Server.MapPath("Docs/") + projectID);<br />
<br />
            // Save the file into the new folder.<br />
            FileUpload.PostedFile.SaveAs(Server.MapPath("Docs/" + projectID + "/" + fileName + extension));<br />
<br />
        }<br />
    }//end of method

    protected void btnLink_OnClientClick(object sender, EventArgs e)<br />
    {<br />
        String pid = Convert.ToString(Session["pid"]);<br />
        String[] file = System.IO.Directory.GetFiles((Server.MapPath("Docs/")+ pid +"/"), "myDesiredFileName.*");<br />
Response.Redirect(file[0]);<br />
}