part4-4

<system.web>
    <!-- For IIS 5 and 6, and the Visual Studio Development Server -->
    <httpHandlers>
        <add path="*" verb="*"
             type="MvcErrorHandling.MvcHelpers.CustomHttpNotFoundHandler"/>
    </httpHandlers>
</system.web>

...

<system.webServer> 
    ...  
    <!-- For IIS 7+ -->
    <handlers>
        <remove name="BlockViewHandler"/>
        <add name="BlockViewHandler"
             path="*" verb="*"
             preCondition="integratedMode"
             type="MvcErrorHandling.MvcHelpers.CustomHttpNotFoundHandler"/>
    </handlers>
</system.webServer>