AjaxMin task has been declared or used incorrectly, or failed during construction - asp.net-mvc-4

Question

I'm trying to add Microsoft's AjaxMin to VS2012 project and I'm not really sure what I'm doing. I think I'm missing something obvious.
I copied the code from the tutorial here (http://ajaxmin.codeplex.com/wikipage?title=AjaxMinTask)
And I've tried adding the reference to my project so my code looks like this:
<UsingTask TaskName="AjaxMin" AssemblyFile="$(MSBuildProjectDirectory)\Build\AjaxMinTask.dll" />
<Target Name="AfterBuild" >
<ItemGroup>
<JS Include="**\*.js" Exclude="**\*.min.js;Scripts\*.js" />
</ItemGroup>
<ItemGroup>
<CSS Include="**\*.css" Exclude="**\*.min.css" />
</ItemGroup>
<AjaxMin JsSourceFiles="#(JS)" JsSourceExtensionPattern="\.js$" JsTargetExtension=".min.js" CssSourceFiles="#(CSS)" CssSourceExtensionPattern="\.css$" CssTargetExtension=".min.css" />
</Target>
This is at the bottom of my .csproj file where there was already a commented out AfterBuild section. I get errors saying JS, CSS, AjaxMin are invalid child elements. When I try to build the project I get an error, I'm not sure what I am missing. I created a folder in the project called Build and added the AjaxMinTask.dll. I don't know if there's any additional thing i need to do to make sure it is referenced properly.
I've also tried using the Import node instead of the UsingTask
<Import Project="$(MSBuildExtensionsPath)\Microsoft\MicrosoftAjax\AjaxMin.tasks" />
And I think AjaxMin is installed correctly because I can run it from command line.

Answer 1

In your .csproj, the end of the document (I've included the last closing element ) should look something like this:
<Import Project="$(MSBuildExtensionsPath32)\Microsoft\MicrosoftAjax\AjaxMin.tasks" />
<Target Name="AfterBuild" AfterTargets="CopyAllFilesToSingleFolderForPackage" Condition="'$(Configuration)'=='Release'">
<ItemGroup>
<JS Include="scripts\*.js" Exclude="scripts\*.min.js;" />
</ItemGroup>
<ItemGroup>
<CSS Include="css\main.css" />
</ItemGroup>
<AjaxMin Switches="-global:jQuery,$" JsSourceFiles="#(JS)" JsCombinedFileName="scripts\combined.min.js" CssSourceFiles="#(CSS)" CssSourceExtensionPattern="\.css$" CssTargetExtension=".min.css" />
</Target>
</Project>
As I am using Windows 7 64-bit, you will see the path of Import... includes (MSBuildExtensionsPath32). If you are using Windows 32-bit, then you do not need the 32 at the end. Other then that, your code should work.
Disregard the JS, CSS, AjaxMin childelements error. But you should not get a built error. If you could post your built error, it would be useful.
Also, the code above combines multiple JS files, just added for fun.