Check out example codes for "HOW TO CALL AN EXTENSION METHOD FOR VIEW C#". It will help you in understanding the concepts better.

Code Example 1

<pages>
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Routing" />
    <add namespace="System.Linq" />
    <add namespace="System.Collections.Generic" />

    <add namespace="MyProject.Extensions" />
  </namespaces>
</pages>

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