title: winform auto close if main form is closed
body: <p>I have two .net 2 winforms, each has its own project. project 1 is main form and project 2 is a child form. and now I would like to know how to make the child form close it self if main form is no longer active.</p>
  
  <p>killing child form on exit doesnt work, because main form can be killed by task manager.</p>