Stay on MdiChild till closed

Question

Hello:
 
I have a MDI parent form called FormICEPack and a MDI child called FormLogin.
 
I want to stay on the FormLogin until the FormLogin has set a variable LoginPass to true;
I spent 2 hours trying to figure it out, so now I am asking the forum for a sample on how I can do it. Anyone have a solution for my issue or where I can go to see a sample?