How to use txtboxes and Combo boxes in a form

Hello Foro
Access 3003.
In a form I'm trying to design a search where user only enter data in three
textboxes.
In a query I have the following parameter :

Like [Forms].[Form].[txtName] & "*"
Like [Forms]![Form].[txtCity] & "*"
Like [Forms].[Form].[txtStreet] & "*"

The fields: OO1, YY1, RR1 do not have parameters but they displays records
in the query as I mentioned here.

The query displays records in the fields
AZ1, AZ2, AZ3, AZ4, AZ5 and AZ6

In the form, I would like to add two combo boxes but with this conditions.
If user select a row from Combo box1 the Combo box 2 must be disabled and
the textboxes as well
If user select a row from Combo box2 the Combo box 1 must be disabled and
the textboxes as well.

Please could you suggest how can I do this?

Many thanks