Same problem here, clearly javascript related. When I looked at my add-ons I had several Java Consoles, different versions, installed. I removed all of them and the problem was no more.

Hi Hamstermandat

Many thanks for your suggestion. I uninstalled all the java consoles and the problem stayed. But just now removed Boost (a Firefox addon for Facebook) and i checked a friend list to suggest a friend and no Javascript message. I think that something in Boost caused that problem. Thanks again....happy facebooking! x

I forgot to put my name, I really have no idea how to use these sites.....Thanks again, Sharon

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems

If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears. You can use "Disable all add-ons" on the Safe mode start window. You have to close and restart Firefox after each change via "File > Exit" (on Mac: "Firefox > Quit")

Thanks to both of you for taking the time to reply. I have not had any problem since uninstalling the Boost add on. So that seemed to have been the problem. Thanks again, Sharon