void DlgCompareDir::DoBrowse(Ctrl *field)    // field is EditString or similar Ctrl
{
	FileSel fsel;
	fsel.AllFilesType();
	static String recent_dir;                  // variable to store last opened directory
	fsel <<= Nvl((String)~*field, recent_dir); //before opening, we pre-set the dialog to the value in field, fallback to recent_dir if there is Null
	if(fsel.ExecuteSelectDir())                //open the dialog to select directory
		*field <<= recent_dir = ~fsel;     // assign the selected directory 'recent_dir' and also fill it into 'field' Ctrl
}

String mydir = SelectDirectory();