Hi, I have a members database with member info. I have Member dues for lets say $300 and three voluntary contribution options as check boxes each contribution has a set price like $65, $25 and $25. I put a calculated control box named total amount paid, but having problems with the formula. I would like the control box to recognize when the check box was selected and once selected add that amount to their mandatory dues amount and show their total amount paid. Any help. Al Guzman

Sum(Iif([CheckBox]=True,[YourField],0))

In the AfterUpdate events of each of the four money fields put:
= Nz(me.fld1,0) + Nz(me.fld2,0) + Nz(me.fld3,0) + Nz(me.fld4,0)

You also need to place this calculation in the OnCurrent event to calculate the amount as each new record is displayed.