callback for a windows form?

i've got a form being created and shown as follows:

//TestProj::dialogInit^ dlg = gcnew TestProj::dialogInit();
//dlg->Show();

but when i do this, the form shows up and code continues as normal. i want the code to only continue when the form is closed. i tried a loop but when i do that, the form never responds/refreshes. I assume there needs to be a callback function somehow but i dont know how to make that work for a windows form. where do i declare/supply the callback as an argument, and what kind of callback is it exactly? That kind of stuff. Thanks in advance.