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'
<compilation debug ="true" targetFramework="4.0"/>
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:
and don't have to write any
using in the code.