HELP: JAVA not working in TEXTPAD

I once installed JDK, it was working well with textpad except that the codes don't have colors, then I uninstalled it because I was kind of hoping that if I'm going to re-install it, the codes will have colors. The codes have colors now, but I keep getting the error: "Could not find or load main class". I can't run any programs now. I've already edited the PATH and CLASSPATH in system properties. And when I tried to use the configure>preferences>tools>add, the option JAVA Sdk commands didn't appear. What should I do? Please help me.