Ask a filename without using Microsoft Common Dialog Control

I invented this function in the pre-Codeunit 412:"Common Dialog Management" era.

AskFile(VAR PtexFileName : Text[1024];pblnImport : Boolean) : Boolean
// AskFile
// IMPORTANT : you can also use Codeunit 412:"Common Dialog Management"
// Asks the user for a filename
// PARAMETERS :
//   VAR PtexFileName : INPUT : Default filename 
//                              (a defaultname, default path or default extension can be given)
//                      OUTPUT : Selected filename
//   pblnImport : TRUE : select filename for import/reading
//                FALSE : select filename for export/writing

ltexHelp := PtexFileName;
IF pblnImport THEN BEGIN
  ltexHelp := lrecObject."BLOB Reference".IMPORT(ltexHelp,TRUE);
END
ELSE BEGIN
  lrecObject.SETRANGE(Type,lrecObject.Type::Table);
  lrecObject.FIND('-');
  lrecObject.CALCFIELDS("BLOB Reference");
  ltexHelp := lrecObject."BLOB Reference".EXPORT(ltexHelp,TRUE);
END;
IF ltexHelp <> '' THEN
  PtexFileName := ltexHelp;
EXIT(ltexHelp <> '');

Use it like this:

LtxtHelp := txtTheFileName;
IF AskFile(LtxtHelp,TRUE / FALSE) THEN
  txtTheFileName := LtxtHelp;

The IF THEN is needed to avoid that the value in "txtTheFileName" is removed if the function is called but then cancelled.