title: Access mainpage content from other page loaded in frame
body: <p>I'm developing a program in C# &amp; XAML where my MainPage has two frames, one of which is an entire page.</p>
  
  <p>I want to load another page inside the Inner frame of MainPage, which has a number of buttons. By pressing one of them, I want to load the Third Page in my Whole Page Frame (bigger frame).</p>
  
  <p>Any suggestions to make this happen?</p>