How do I:MDIParect calls MDIChild... MDIParent wait till MDIChild close to continue.

Question

Hello:
 
I have a MDIParent that calls an MDIChild. Within the MDIParent there is code right after the call to the MDIChild. I do not want the code to be executed untill the MDIChild closes. I have tried to call the MDIChild.ShowDialog() but I cant get it to work. Can someone help me out?