/// <summary>
/// Downloads (pushes) file to the client browser. 
/// **** NOTE **** Cannot be done from inside an AJAX UpdatePanel control.
/// </summary>
/// <param name="fullFilePath">The full file path of the file</param>
protected void DownloadFile(string fullFilePath)
{
 // Gets the File Name
 string fileName = fullFilePath.Substring(fullFilePath.LastIndexOf('\\') + 1);
 byte[] buffer;
 using (FileStream fileStream = new FileStream(fullFilePath, FileMode.Open))
 {
  int fileSize = (int)fileStream.Length;
  buffer = new byte[fileSize];
  // Read file into buffer
  fileStream.Read(buffer, 0, (int)fileSize);
 }
 Response.Clear();
 Response.Buffer = true;
 Response.BufferOutput = true;
 Response.ContentType = "application/x-download";
 Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
 Response.CacheControl = "public";
 // writes buffer to OutputStream
 Response.OutputStream.Write(buffer, 0, buffer.Length);
 Response.End();
}