Acrobat javascript to check muliple checkboxes with one click?

I have about 60 checkboxes in a document. I am trying to set it up so that there is one 'master' checkbox so that if that one checkbox is checked, they all become checked.

My boxes are named checkbox.0, checkbox.1, checkbox.2, etc.

My javascript is run on mouse up and is:

var f = this.getField("checkbox");
f.checkThisBox(0,true);

Which does nothing. If I add a '.0' to the end of 'checkbox', it will check box checkbox.0:

var f = this.getField("checkbox.0");
f.checkThisBox(0,true);

This works, but I want to check ALL the checkboxes.