Help with Safari radio button selection

Hi, I’m new to both AppleScript and JavaScript. Thanks to a lot of previous posts, my AppleScript will log in with username and password to a Safari page just fine, but on the next page I can’t figure out the Javascript to select a radio button, and can’t find a post on this. Tried lots of variations on:

set y to "document.forms[0].elements['count[2].click()'];"
tell application "Safari" to do JavaScript y in document 1

to select the third radio button, but only get the first one. Here’s the source:

25 50 100 Companies

Any help would be much appreciated! Thanks,

AppleScript: 2.1.1
Browser: Safari 419.3
Operating System: Mac OS X (10.4)