Listing 4: getErrorDescription Function

function getErrorDescription(n) {
  var tempname, cmdline, ts, result;

// BEGIN CALLOUT A
  // Create a temporary filename.
  do
    tempname = FSO.BuildPath(FSO.GetSpecialFolder(TEMP_FOLDER),
      FSO.GetTempName());
  while (FSO.FileExists(tempname));
// END CALLOUT A

  // Construct the command line.
  cmdline = FSO.BuildPath(FSO.GetSpecialFolder(SYSTEM_FOLDER), "cmd.exe") +
    " /c " + FSO.BuildPath(FSO.GetSpecialFolder(SYSTEM_FOLDER), "net.exe") +
    " helpmsg " + n.toString() + " > \"" + tempname + "\"";

  // Run the command and wait for it to finish.
  WshShell.Run(cmdline, 0, true);

  try {
    ts = FSO.OpenTextFile(tempname, FOR_READING);
    result = trim(ts.ReadAll());
  }
  catch(err) {
    result = "";
  }
  finally {
    ts.Close();
    FSO.DeleteFile(tempname);
  }

  if (result == "")
    result = "Could not find an error description for error number " +
      n.toString() + ".";

  return result;
}