cannot Imports System.Web.Script.Serializer <p>when I try to append this line to the code:</p> <pre><code>Imports System.Web.Script.Serializer </code></pre> <p>it showing me error like this:</p> <blockquote> <p>Namespace or type specified in the Imports 'System.Web.Script.Serializer' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.</p> </blockquote> <p>then I searching references in google, say that should <code>Add References</code> then choose System.Net.Extension.dll in .NET tab, but it not found in the list</p> <p><img src="https://i.stack.imgur.com/HDT4K.png" alt="enter image description here"></p> <p>I try to import the System.Net.Extension.dll with manually. I open <code>Add Reference</code> dialog, in <code>Browse</code> tab, I select <code>System.Web.Extension.dll</code> in <code>C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0</code>, then klik Ok. but it still doesn't work instead show me error message agains like this:</p> <p><img src="https://i.stack.imgur.com/D09vt.png" alt="enter image description here"></p> <p><img src="https://i.stack.imgur.com/cRVQW.png" alt="enter image description here"></p> <p>whats wrong with my VS2010 ??</p>