Here's a short example:

procedure TForm .Button Click(Sender: TObject); var OldErrorMode : Integer; fp : TextFile; begin try OldErrorMode := SetErrorMode(SEM_FAILCRITICALERRORS); try AssignFile(fp,'A:\foo.bar'); Reset(fp); CloseFile(fp); finally SetErrorMode(OldErrorMode); end; except on E:EInOutError do if E.ErrorCode = 2 then ShowMessage('Drive A: is not ready...'); end; end; 7/ 6/98 4:3 :28 PM