Create text field where total = Fail

[ScoutDispatch]

I have a simple form with a column of check boxes.  The value of each checkbox is one.

I want the text field to do a simple calculation of the total, done, no problem.

However, the next step I do need help with is to make that text box say Fail if the quantity of checkboxes is over a certain quantity.

Example:  There are 30 checkboxes

If 9 checkboxes are marked then text field should say Fail.

I know this is a very simple issue for most of you but I have not used adobe in years and never needed calculations.

Thank you for your time and patience. 

[Nesa Nurani]

Since you already have total calculated as 'Validation' script of that text field use this:

if(event.value > 8)event.value = "Fail";