I've set up my post build config as demonstrated at http://www.asp.net/ajaxlibrary/ajaxminquickstart.ashx

I'm getting the following error though:

The "JsSourceFiles" parameter is not supported by the "AjaxMin" task. Verify the parameter exists on the task, and it is a settable public instance property.

My configuration settings......

<Import Project="$(MSBuildExtensionsPath)\Microsoft\MicrosoftAjax\ajaxmin.tasks" />
<Target Name="AfterBuild">
<ItemGroup>
  <JS Include="**\*.js" Exclude="**\*.min.js" />
</ItemGroup>
<ItemGroup>
  <CSS Include="**\*.css" Exclude="**\*.min.css" />
</ItemGroup>
<AjaxMin 
    JsSourceFiles="@(JS)"  JsSourceExtensionPattern="\.js$" JsTargetExtension=".min.js"
    CssSourceFiles="@(CSS)" CssSourceExtensionPattern="\.css$" CssTargetExtension=".min.css"  />
</Target>

I had a look at the AjaxMinTask.dll with reflector and noted that the publicly exposed properties do not match the ones in my config. There is an array of ITaskItem called SourceFiles though so I edited my configuration to match.

  <Import Project="$(MSBuildExtensionsPath)\Microsoft\MicrosoftAjax\ajaxmin.tasks" />
  <Target Name="AfterBuild">
    <ItemGroup>
      <JS Include="**\*.js" Exclude="**\*.min.js" />
    </ItemGroup>
    <ItemGroup>
      <CSS Include="**\*.css" Exclude="**\*.min.css" />
    </ItemGroup>
    <AjaxMin
        SourceFiles="@(JS);@(CSS)"  SourceExtensionPattern="\.js$;\.css$" TargetExtension=".min.js;.min.css"/>
  </Target>

I now get the error:

The "SourceFiles" parameter is not supported by the "AjaxMin" task. Verify the parameter exists on the task, and it is a settable public instance property.

I'm scratching my head now. Surely it should be easier than this?

I'm running Visual Studio 2010 Ultimate on a Windows 7 64 bit installation.