title: How do I detect when a web page is loaded?
body: <p>I want to write an application that detects when a page is loaded in the browser, then I should be able to insert content on top of the loaded web page? Anybody with an idea on how to do that?</p>
  
  <p>Please note that I should be able to do this in any browser (Firefox/IE).</p>
  
  <p>What language should I use to help me do this?</p>
  
  <p>How do I detect this from an external application?</p>
  
  <p>How should I integrate this with the browser?</p>