I was needing to use Mathlink to call some c++ code so I thought I would learn from the basic examples but I am running into strange issue. Following the procedure outlined from the Mathematica Documentation Center I attempted to do the very simple addtwo.exe build. I followed as exactly as I could(since this was written for Visual Studio 2010 some of the names of things weren't exactly the same). When I did the portion where you build addtwo using the Visual Studio Command Line Tools it works great. However, when I try to do the method outlined at "Using the Integrated Development Environment Visual Studio 2010" I get that it isn't able to find the right libraries. And get the following:

1>------ Build started: Project: addtwo, Configuration: Debug Win32 ------
1>addtwo.obj : error LNK2019: unresolved external symbol _MLMain referenced in     function _WinMain@16
1>addtwo.obj : error LNK2019: unresolved external symbol _MLInitializeIcon     referenced in function _WinMain@16
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


I have moved, as directed by the tutorial, all the libraries etc. to their respective folders in the path "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC" (so \bin \lib \include). I am guessing perhaps I don't have something set up correctly it just confuses me that it would work with the Command Line but not with the IDE method. (I am following the 32 bit tutorial from the website)

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Possible duplicate of mathematica.stackexchange.com/questions/41682/…. – Sjoerd C. de Vries Apr 9 '14 at 18:54
I gave this a try but unfortunately it didn't work. Perhaps there is another file I would need to edit since 2013 isn't yet supported officially for Mathematica 9. It isn't imperative that I be able to use the IDE. – user573214 Apr 9 '14 at 20:45
I tried this as well and it didn't help. I am not seeing where vcvarsamd64.bat is mentioned though? – user573214 Apr 13 '14 at 23:17
It's in the comments below the question. You have to fold open the list as it is partly hidden. – Sjoerd C. de Vries Apr 14 '14 at 5:25

All the former ML* functions now start with WS*, mathlink.h is now wstp.h. When you still get linker errors, try dragging and dropping the file

or

If you drag-and-drop add a .lib file to your project, you don't have to specify and #pragma comment(lib, "...") or Library Directories or Additional Dependencies.
They renamed MathLink to WSTP for marketing reasons. They also changed functions from ML to WS naming. This broke both source and binary compatibility. For backwards compatibility, now Mathematica ships with two sets of tools/libraries: one is in SystemFiles/Links/WSTP and the other is in SystemFiles/Links/MathLink. They have the exact same functionality. When one gets updated in a new version, so does the other. But they are incompatible with each other in the sense that they cannot be mixed: Use WS and link to WSTP or use ML and link to MathLink, but don't mix. – Szabolcs Jun 19 at 10:16