不同的xcode版本之间的iPhone编译？

Hi I am just starting to develop Iphone apps, it's my first day. And I have to use some code a colleague gave me (he has xcode 4.1 or 4.2) l just to quickly try it out but It doesn't compile and I don't understand why. I have iphone SDK 3.1 and xcode 3.2 (i think). Updating to any other version is out of the question so is there a way I could fix these compilation errors? I get the following errors in iLikeItAppDelegate.mHi I am just starting to develop Iphone apps, i