[RESOLVED] Can't find InsertOnSubmit() method

I'm new to Entity Framework , and I'm think there is something that I misunderstand here.
I'm trying to insert a row in a table, and everywhere I found code example, they call the method InsertOnSubmit(), but the problem is that I can't find anywhere the method InsertOnSubmit, or SubmitChanges.


The error tell me:
System.Data.Object.ObjectSet<WorkBench.tblConfig> do not contain the definition for InsertOnSubmit, ...

What I'm doing wrong??


http://msdn.microsoft.com/en-us/library/bb763516.aspx

Code:

---

            GMR_DEVEntities CTX;
            CTX = new GMR_DEVEntities();
            tblConfig Config = new tblConfig { ID = Guid.NewGuid(), Code = "new config code" };
            CTX.tblConfigs.InsertOnSubmit(Config); // Error here

---

Edit:
Using Visual Studio 2010 on FW 4.0

Finally found what was wrong, my Entity database was a dbmx file and not a dbml file.