I have a check if a data file is opened as shown in the code below. It
works ok, but my problem is that afterwards, instead of staying in the
same dialog and allow me to enter another data file, it proceeds to the
next dialog. How can i refresh the same dialog for a second chance to
enter another file?

 if (!datafile.is_open())  //checks to see if file opens successfully
 {
  MessageBox("The file was not opened.\n Please retry", "Error message",
MB_OK | MB_ICONINFORMATION);
 }

Thanks,
Elias