Ok,

First, both of th below are replacing the value in the same textbox. Thisform.txt2.

>&& BOARDFOOTAGE
>Thisform.txt2.Value = val(thisform.c11.Displayvalue) * ThisForm.lnCol2Value * ThisForm.lnCol3Value * val(thisform.c31.Displayvalue)
>
>&& LINEAL BOARDFEET
>Thisform.txt2.Value = val(thisform.c11.Displayvalue) * ThisForm.lnCol3Value * val(thisform.c31.Displayvalue)
>
>there are 3 combos, one with values 1-20, the second with the previously mentioned array, and the third with even numbers through 20.
>

I'm not exactly sure what's happening but...

Do all the combo's show a value when the form starts? If not in the init of each combo do something like:
this.value = 'SomeValueInTheList'

Now, let's move the actual calculations to a form method. In the form add a method called 'CalcBrdFeet' and 'CalcLnlFeet'. You do it the same as adding a property. Click Form, then method.

Once those are added doubleclick the form and change it to one of the methods you just added and place the code to do each calculation in it's appropriate method.

In the forms init event add the following code:

ThisForm.lnCol2Value = ThisForm.c21.aList(ThisForm.c21.ListItemID, 2)
ThisForm.lnCol3Value = ThisForm.c21.aList(ThisForm.c21.ListItemID, 3)

thisform.CalcBrdFeet()
thisform.CalcLnlFeet()

This should fill in the text boxes with the correct values at start.

In c21's IAC event put the following:

ThisForm.lnCol2Value = ThisForm.c21.aList(This.ListItemID, 2)
ThisForm.lnCol3Value = ThisForm.c21.aList(This.ListItemID, 3)

thisform.CalcBrdFeet()
thisform.CalcLnlFeet()

In c11 and c31's IAC put:

thisform.CalcBrdFeet()
thisform.CalcLnlFeet()

Now when you change any of the combos it should update the textboxes.

hth