Cathi:

Found the problem, was a simple syntax error,
Incorrect *****
Dim SocSecNum As New Binding("Text", ObjDatos_personales_sol1, "num_control")

Correct

Dim SocSecNum As New Binding("Text", ObjDatos_personales_sol1, "datos_personales_sol.num_control")

Now is formatting the social security number but in the old fashion, it convert the number after you finished typing and move to the next control.

Question?

Can Be posible to apply the dash "-" on a fly? I have to create another handle to keypress ?

Let me tell you that I follow your recomendation, I create another form as a test and apply my connection , my data adapter, my dataset and all the routine and get the same error message so I decide go back to the original thread and try to see the difference between the code and figure out that I did not make reference to the table in the declaration only to the member.