font resizer question

The font font-resizer plugin works good on my site but when I click on the 3rd AAA’s it kinda gets bigger as you click on it.. My question is what is the code so that they AAA doesn’t change it’s size meaning if I click on the 3rd A than the font changes on the site but not the AAA’s? I want it to stay put and not go all over the place when I click on them,,