title: How do I implement method swizzling?
body: <p>I am trying to modify behaviour of a program (i dont have it's source) using SIMBL. I used class dump and found out that I need to overide an instance method</p>
  
  <p>This method is in the class called controller. All I need to do is get the argument arg1 and thats it. Maybe NSLog it or post a notification...
  I read about method swizzling in objective-c but how can I use it?. I would need to refer to the class MessageController whose course i don't have.</p>
  
  <p>Thanks!</p>