error LNK2019: unresolved external symbol

[wee3200]

Hello, I'm using Microsoft Visual Studio 2003.
And Actually i am using the snake game coding from this youtube user.
http://www.youtube.com/watch?v=oMaXdnJgWUk

I can compile the code successfully, but i can't build&run the code.

this is my error code below: (and sorry for my bad english)
snake error LNK2019: unresolved external symbol "void __cdecl items(class std::vector<int,class std::allocator<int> > &,class std::vector<int,class std::allocator<int> > &,int &,int * const,int * const,int &,int,int,int &)" (?items@@YAXAAV?$vector@HV?$allocator@H@std@@@std@@0AAHQAH21HH1@Z) referenced in function "void __cdecl Update(int &,int * const,int * const,int * const,int * const,int &,int &)" (?Update@@YAXAAHQAH11100@Z) snake fatal error LNK1120: 1 unresolved externals

Sorry one more question, i wish to post my source code but the coding have reach the length limited, or may i post my source code with two replies?

[kbw]

Have you defined the function items? The linker is saying it's called from Update, but it can't find it. You must have the prototype available or the compile of Update would have failed.