How to make nested child forms in C#.net

In my win开发者_JAVA技巧dows form application I am using 10 forms.It is fine when only a parent and single child form are used at a time. But in case of multiple use of child form I am getting problem and not able to use them as child forms.They are not working as child form. Your any effort would be helpful for me.

Thanking You In Advance

A child form's MdiParent property need only be set to your MDI container form. Make sure the MDI form's IsMdiContainer = true.

foreach (Form myForm in ChildForms)
    myForm.MdiParent = myMdiContainer;   // alternatively use 'this'