Updating Line No. field on inserting a record


I have created 2 tables FOC Header and Foc Line and 2 forms for the these tables. In the header i do F3 and insert a record. When I come down to the line part, and insert fields and come down to the next line the “Line No.” field should get updated. Can anyone help me how do I go with this… Now if i go to the second line in the line part its not allowing me to insert another line… its giving the error as… “FOC Line already already exists… Identification fields n values… No. = FOC/12-13/001”.

Thanks in advance…

Check the Sales Lines Table & Form for auto split & line No. field.

Cause line no. gets auto increment.