How To add new namespace in C# : I am creating MVC project behind i am using C# code. i have 

    `CloudConfigurationManager`

  in using read  db value . its  showing red Error . i have searched google i need to add  namespace. 
`using Microsoft.Azure;` 

i  have added that also  but again Getting Error Like this 

    type or namespace 'Azure' does not exist in the namespace  'microsoft' (are you missing  an assembly reference?)  showing like this  how to fix this issue how can i add namespace Azure?