Error: Unable to find an enry point named FUNCTIONNAME in Dll DLLNAME

I have a third party dll and I am sure that it is not an activeX or dotnet
assembly .
I have check it up with Dependency Walker software and found the list of
it's exported function in C++ syntax
for example :

void __cdecl TelEnd(void)
void __cdecl FaxStop(void)

and so on ...

I can not call them from VB/VB.NET and I received the following error
message
" Unable to find an enry point named FUNCTIONNAME in Dll DLLNAME "

I use the following declaration :

Declare Sub TelEnd Lib "......\MultiFunc.dll" ()

what is wrong with that?


Thanks
Saman