Trying to compute an average of certain cells

I am trying to compute an average of values on a spreadsheet. The client requires that we keep 30 fields available in the sheet, so even if only 4 are used, the others are to remain blank. We are using an ActiveX button to enter the value.

The denominator of the average seems pretty easy, we just have it count (COUNTA) the number of cells in column B that have information in them. However, column I is presenting a problem, as all of the cells in it have a potential value.

Basically, we want to be able to make the numerator of the equation the value of the buttons that have been "checked", but only if there is data entered in the column "B" of that group of rows. I hope the picture makes things a little clearer.

Right now, the formula reads =SUM(I6:I125)/COUNTA(B6:B125). Obviously, the sum of all those is wrong for that denominator; we want it to only take the data from the cells that have a button clicked. Thank you for any help!

http://img85.imageshack.us/img85/7893/excelsample.png

Hi and welcome to the board

Why post an image when you need a sheet ? Nobody likes to have to retype data...

Thank you for pointing that out, I attached the wrong file! Attached is the spreadsheet.

We have worked through one part of the problem, and are only working on a "dummy-proofing" of the sheet. We would like to make it that the buttons in Column I cannot be selected unless there is text in column B, thus preventing someone from accidentally clicking on a "Exceeds Expectations" rating when there is no objective listed in column B. Any way to make that happen?

Thanks for the quick reply!