Problem with dataform wizard

Question

I want to make employee form for a database project in VB.net. I am using data form wizard. In the database I have an employee table in which I have NIC no as primary key. This table also has foreign keys from 8 tables. But none of the key is required in employee table except nic no. In the dataform wizard I have also created all the relationship. I select single record in individual control. But when i run the project and press Add button it gives this error "Column nic does not allow null" The behavior of navigational buttons is also mysterious. If any one can help me I will be very much great full. Thanks