Reset button to make submit buttons read only

I have a reset button at the end of my PDF.  I want it to make my radio groups not read only and to make my submit buttons read only.  I have the first part working, but not the latter.  Here is my script on the Restart button:

var Q = ["KAQuestion.1", "KAQuestion.2", "KAQuestion.3", "KAQuestion.4", "KAQuestion.5", "KAQuestion.6", "KAQuestion.7"];

for (var i in Q) this.getField(Q).readonly = false; // this part is working to enable the Question radio group options

var S = ["Submit1", "Submit2", "Submit3", "Submit4", "Submit5", "Submit6", "Submit7"];

for (var i in S) this.getField(S).readonly = true; // this part is not working to disable the Submit# buttons

Thank you for your help, in advance