Killing processes by name

Okay is there any way to kill a process by name? Since I've update to RH
7.2 I been noticing that I had problems with mozilla or other apps.
Today I finally thought to check for java_vm processes. there are
*hundres* of them they aren't dying I don't know if that's just because
I have so much memory the garbage collector simply isn't clearing them
or what but I want them dead and I don't wont to have to type in ever
process number. is there a way I can just say kill all java_vm processes?

Carl P.