I\'m using WS class and it gave me error when I run the application:
The type or namespace name \'Entity\' does not exist in the namespace \'System.Data\' <
Thanks every body! I found the solution. not that I understand why but I tried this and it worked! I just had to add a reference to: System.Data.Entity.Design and don't have to write any using in the code. Thanks!
System.Data.Entity.Design
using