You don't really need to use vba, just use the built-in "conditional
formating"
While in design view, you can select this from the format menu. You can
base your format on a particualr value of the current field, or you can
change the fisrt drop down box and enter a formula that evaluates other
fields. In your example, you don't tell us if you are bolding a control
based on that control's value or some other control.