An error during using ChatKit.framework

Question

I used ChatKit.framework in jailbreaked project. When I compile the project, I got a error like this:

Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_xxxxx", referenced from:
      objc-class-ref in main.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I added the ChatKit.framework to project. May I missed something?

Answer 1

I got why: this function removed on iOS6. My SDK is iOS6.1, change to iOS5 SDK is all done.