URGENT! Average function needed!

I am using ACCESS '97 to develop a testing application. This
application  will input 112 values to one record in a database. The
values are to be numbers (0-4) or text (X). My problem is that I need to
average a set of 7 values (from one record) and use that average to plot
to a graph. I have developed the data entry screens and the graphing,
but I can't seem to be able to create a function that can first evaluate
whether the value is a number, discard non-number values and then
average the other values.

I do have fields on a form that I can create a calculated field from.

I know this function can be done because the AVERAGE function in Excel
can easily do this operation.

Please help!

Thanx.

On the After_Update event property have an event procedure with the
following:

If Not(IsNumeric(Me![CtrlX]) Then
        Me![CtrlX]=0    'Or have Me![Ctrlx]=Me![Cntrlx].OldValue, stay away from NULL
                        'NULL will make the Average NULL as well
Else
            Me![Average Control]=(Me![Ctrl1]    +Me![Ctrl2]+ ...
+Me![Ctrl7])/7
End IF

--
Steve Bliss
PS The "bye" before my email name is to prevent spam.
Remove the "bye" if sending me email.