Same Issue with javascript, except I have a mac

hey. i made the mistake of trying to download flashplayer onto my imac running OS X. now i have tried to uninstall flashplayer, supposedly that worked, but now whenever i go to certain sites, i cant use them, like youtube, msn games etc. what am i missing? it usually reads i need to enable javascript (which as far as i can tell is already enabled) or download flashplayer (which i no longer want to do). help