button sets field value

I am positive this is an Acrobat Javascript 101 issue but I am at a loss. Simply put, I am trying to set the value of a text box with a separate button.

I have several text boxes R1_Sat, R1_Marg1, R1_Marg2 and R1_Unsat. The values respectively are 10, 8, 6, 0. They are all part of a calculated score and only one can be chosen. I created 4 different buttons for each. The objective is upon pressing a button, the respective text field value is filled in and the other text fields zeroed. I need to use a button vice radio button unless I can change the location of the "check mark" within the extended button if that makes sense....