How to edit relationships between DB tables in VS 2012?

Question

SQL

I can't edit Relationships between tables

. I can't open the relationship editing window.
Did according to the article

Answer 1

Did it like this:

CREATE TABLE [dbo].[UserRole] (
    [Id]     INT NOT NULL,
    [UserID] INT NOT NULL
 REFERENCES [dbo].[User] (Id)
 ON DELETE CASCADE
    ON UPDATE CASCADE,
    [RoleID] INT NOT NULL
 REFERENCES [dbo].[Role] (Id)
 ON DELETE CASCADE
    ON UPDATE CASCADE,
    PRIMARY KEY CLUSTERED ([Id])
);