LINQ .SubmitChanges not updating SQL DB

New to LINQ - following tutorial video word for word but my SQL DB is not
updating.

Here is my code

 Dim db As New linqJobsDataContext

 Dim j1 = (From j In db.Jobs _
 Where j.JobID.StartsWith("2007013") _
 Select j).Single

 j1.Title = "abc123"
 db.SubmitChanges()



THANKS!!

Also, in debug mode the Jobs table IsReadOnly = True!!!! How do I make the table
editable???

 Thanks

I didn't have a primary key on my table. DUH Also had to drop the table class
and re-add after creating and saving the primary key.