Runescape help please!!!?

When I play I have to download Java Runtime Environment. When I download it it makes my computer go super slow. And when I play Runescape with Java Runtime Environment I can't get ped the "Click here to play now" sign because every time it says Loading Please Wait it freezes and says Connection Lost. Now it does this EVERY time I try to play. I have removed Java Runtime Environment from my computer now. It used to just say Run or Don't Run but know I have to use Java which doesn't work because it's slow. And help? BTW I use Firefox if that does anything. I still have IE but I use Firefox mostly. HELP!!!