DOCUMENT:Q174686  07-OCT-1997  [vbwin]
TITLE   :PRB: Error 371 or 5 Occurs When Using the Show Method
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0
OPER/SYS:WINDOWS
KEYWORDS:vb5all kberrmsg

======================================================================
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The information in this article applies to:

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, version 5.0
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SYMPTOMS
========

When the MDI child form uses the Show method to open a form, you may
receive the following error:

   Run-time Error '371':
   The specified object can't be used as an owner form for Show().

When the MDI child form uses the Show method to open an MDI Child form, you
may receive the following error:

   Run-time Error '5':
   Invalid procedure call or argument.

CAUSE
=====

These errors occur if an MDI child form uses the Show method and specifies
that it owns the form to display. An MDI child form cannot own another
form.

STATUS
======

This behavior is by design.

MORE INFORMATION
================

While you can specify the owner of a form as one of the parameters in the
Show method, you cannot designate an MDI Child form as an owner of another
form.

Steps to Reproduce Problem
--------------------------

1. Start a new Standard EXE project in Visual Basic. Form1 is created by
   default.

2. Add a CommandButton to Form1.

3. Add an MDI form and a second form to your project.

4. Set the MDIChild Property of Form1 to True.

   NOTE: To reproduce the error #5, set the MDIChild Property of Form2
   to True as well.

5. Copy the following code to the Code window of Form1.

      Option Explicit

      Private Sub Command1_Click()
         Form2.Show vbModal, Me
      End Sub

6. Press the F5 key to run the program. Click the CommandButton and the
   error occurs.

Additional query words: mdiform mdichild

 (c) Microsoft Corporation 1997, All Rights Reserved. Contributions by
Arsenio Locsin, Microsoft Corporation
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Keywords          : vb5all kberrmsg
Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbprb

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