C# - Download A File From Remote Server?

The below code works fine for downloading a file from a current pc.plz suggest me how to download it from remote server using ip address or any method

protected void Button1_Click(object sender, EventArgs e)
{
const string fName = @"C:ITFSPDFbillsFebruaryAA.pdf";
FileInfo fi = new FileInfo(fName);
long sz = fi.Length;
Response.ClearContent();
Response.ContentType = MimeType(Path.GetExtension(fName));
Response.AddHeader("Content-Disposition", string.Format("attachment; filename = {0}", System.IO.Path.GetFileName(fName)));
Response.AddHeader("Content-Length", sz.ToString("F0"));
Response.TransmitFile(fName);
Response.End();
}
public static string MimeType(string Extension)
{
string mime = "application/octetstream";
if (string.IsNullOrEmpty(Extension))
return mime;
string ext = Extension.ToLower();
Microsoft.Win32.RegistryKey rk = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext);
if (rk != null && rk.GetValue("Content Type") != null)
mime = rk.GetValue("Content Type").ToString();
return mime;
}