Problems with UTF

Hi, I have a php based script that is called from a html page via ajax. Everything runs fine except when I use characters such as á that ends up like A! After searching and testing I found that if I remove the encodeURIComponentfrom the javascript and replace with escape everything works fine. So the question is what can I do from PHP side to make it play nice with those UTF encoded chars generated from encodeURIComponent? Since escape is deprecated I'd like to find out before I have tons of files to change.... tks.