Check Box = a value but only one box in a group can be checked

[Mgundel]

Checkboxes - Exceed2, Exceed5, Exceed6

Text Fields - Exceed Count 2, Exceed Count 5, Exceed Count 6

I have a column for an employee performance documents with 3 rows of items (Exceed2, Exceed5, Exceed6).  Each row has a checkbox, that if it is checked it will give the corresponding textbox beside it a value of 2.  If unchecked it will be blank.  I have gotten this to work using the custom calculation script.  This is the formula I used.

if (this.getField("Exceed2").isBoxChecked(0))
event.value = 2;
else
event.value = "";

My issue is I only want one of the checkboxes to be able to be checked at a time.  Is this possible?  If not, is it with radio buttons?  

[Nesa Nurani]

It's possible, give all 3 checkboxes same name but give them different export value.

[Thom Parker]

Read this primer on Checkboxes/radiobuttons in Acrobat:

https://www.pdfscripting.com/public/Checkboxes-and-Radio-Buttons.cfm