Those damn DLL's..should be an easy question

I am trying to get a handle on DLL procedures. I know there are preprocssor directives and batch build files but I just wanted to do up a SIMPLE project so that I would understand the DLL linking process before trying any of the more advances stuff.
I basicly had in mind an app that would call a simple function in a DLL so that I could understand the process.
My MainApp is a simple dialog based app with a push button that should call the message box in the DLL.
The DLL builds with no problems.. 0 warnings  0 errors

However when I try to build the main app I get a linking error.

Does anyone have any ideas as to where I am going wrong??

To keep it VERY simple , I have not changed any compiler options other than to check the dependency in the MainApp program.

Thanks.

Here are some code samples.
Both projects were build using the wizard and reside in the same work space.
I manually copied the DLL,lib and exp file into the MainApp paths (all of the paths just ot be on the safe side).
It doesn't work!
MyDLL is a DLL project.
MyMainApp is the exe project.


MyDLL.h contains:
_declspec(dllexport) void ShowMeMessage();

MyDLL.cpp contains:
_declspec(dllexport)
void ShowMeMessage()
{
MessageBox(0,"This is inside the DLL","DLL SUCCESS",MB_OK);
}


MyMainApp.h contains..
_declspec(dllimport)ShowMeMessage();

MyMainAppDlg.CPP contains

#include "MyMainAppDlg.h"
#include "MyMainApp.h"


void CMyMainDlg::OnGetdll() //Push the Dialog buttonn and this should happen....
{
     // TODO: Add your control notification handler code here
     MessageBox("This is the button press","STILL INSIDE APP",MB_OK);
     ShowMeMessage();     // DLL function
}
Then the following error codes are generated..

Generating Code...
Linking...
MyMainAppDlg.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) int __cdecl ShowMeMessage(void)" (__imp_?ShowMeMessage@@YAHXZ)
Debug/MyMainApp.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.