Mdi Parent and Child

Hello!
I have a Parent Form. From it i load another form, a normal form and from it a child form for the Parent form. My code sounds like this:

//this is the code from the intermediate form (normal form)
admpanel_form admform=new admpanel_form(); //this is the Parent form
vizualizare_form form1 = new vizualizare_form(); //this is the child form that i want to load in                                                                         admpanel_form
form1.MdiParent =admform; //setting the Parent admform for form1
form1.Show();

So it seems it is not working.
Please help me!