Combo is Null Function Help

[fabian1675]

Hi I have a form that contains 4 combo boxes:

Combo box:
A1 A2
B1 B2

What I would like to do is when A1 has a value in it I want the corresponding data from A2 to be available and B1 and B2 to be grayed out not selectable, likewise when B1 has data in it I want the corresponding data from B2 to be available and if both either A1 or B1 is null I would like to have a message box to promp the user to enter data in either A1 or B1

I don't know if this matters but I'm using access 2007



Thanks much in advance

[orange]

Do some research on Cascading combo boxes.
http://www.baldyweb.com/CascadingCombo.htm
http://www.datapigtechnologies.com/f...combobox1.html
http://www.datapigtechnologies.com/f...combobox2.html