Combo box ACCESS 2003

HI...

IM HAVING SOME ISSUES WITH MY COMBO BOX IN A FORM.......

THE FORM HAS THE DATA ENTRY = YES..

IF I DONT CHOOSE NOTHING ON THE COMBO BOX AND CLOSE MY FORM IT DOESNT HAPPEN NOTHING, NO RECORDS ARE SAVED, BUT IF I SELECT A VALUE FROM THE COMBO BOX WITHOUT DOING CLICK IN MY SAVE BUTTON IT SAVE THAT RECORD... HOW CAN THIS BE???? BASICALLY IF I CHOOSE A VALUE FROM THE COMBO BOX IT IS SAVED IN THE DB.


ANY IDEAS??