How to identify if a webpage is being loaded inside an iframe or directly into the browser window?

Question

I am writing an iframe based facebook app. Now I want to use the same html page to render the normal website as well as the canvas page within facebook. I want to know if I

Answer 1

Write this javascript in each page

if (self == top)
  { window.location = "Home.aspx"; }

Then it will automatically redirects to home page.