Windows Form Closing Automatically When Parent Window Gets Focus?

VB Windows form Application.. I am developing an application of which part of the program is around configuration settings allowing the user to enter configuration items. When the menubar item for configuration menu is clicked on the main form the menu opens.This is fine but the mainform should not become active again until the configuration menu has closed. This does not happen right now and the mainform simply comes to the foreground and the configuration form goes to the background... I realize that coding an event on the Child form to handle this would not work because the child window loses control and the main form gains control.. I thought of coding a function as follows on the main form but it does not seem logical because i would have to add to it for everyform and do checking to make sure the child is actually open before trying to close it..

Private Sub Form1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.GotFocus
MailSettingsWindow.Close()
RentalSettingsWindow.Close()

[code]....

I did away with the above sub routine and used the below code as per the recomendation of using showdialog which works just as i was looking for.

Private Sub MailingAndEmailSettingsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MailingAndEmailSettingsToolStripMenuItem.Click
Dim MailConfig As New MailSettingsWindow()
MailSettingsWindow.Showdialog()
End Sub