No previous prototype for function
===

I'm adding [this tone generation code][1] to an existing project of mine but I'm doing something wrong and can't figure out what the problem is. The code works fine in the stand alone project.

In the controller where I'm adding the code I only have warnings saying `No previous prototype for function 'RenderTone'` (repeatedly)

I'm also getting a few errors but these aren't located in the source files I've written myself:

![enter image description here][2] 

Any idea what could be causing those?


  [1]: http://cocoawithlove.com/2010/10/ios-tone-generator-introduction-to.html
  [2]: http://i.stack.imgur.com/shf4t.png