interpreter

Sign language interpreter at Nelson Mandela's memorial was a fake | The Verge WTF, seriously i dont know whom to blame

i have windows XP sp1, athlon 2000+, 256Mb RAM and nforce m/b with 40GB baracudda. i recently installed JDK1.5. the problem is that when i compile my program from console, they compile fine, but when i exceute them with (java) interpreter i get an error : exception in "main"...