undefined reference to `Calss::function()'

[kww228]

As the title states I am getting this error in my program yet I am at a loss and have tried everything I could think of to fix this. Why am I getting this error and how can I fix it? When I change line 51 from lotAMenu(); to lotAMenu; obviously the first one is what is needed, but I am trying everything. I have included my code below.

http://codeviewer.org/view/code:470d (parkingControl.h)
http://codeviewer.org/view/code:470e (parkingControl.cpp)
http://codeviewer.org/view/code:470f (parkingLotGateA.cpp)
http://codeviewer.org/view/code:4710 (parkingLotA.h)

[Disch]

'undefined reference' typically means you are calling a function, but the linker cannot find the body of that function anywhere. (IE, it is prototyped, but you never wrote any code for the body)

The error should tell you exactly which function is the culprit. Read that and check to make sure the function is question has a body.