ok give a try to following
find out if there is any entry for java, like /usr/java/jre_ver/bin:
find out where jre 1_5_0_03 is installed
usually jre is installed in /usr/java/jre_ver but if ain't there try finding
Code:
locate jre 1_5_0_03
add following to /etc/profile ( replace /path_to_jre/jre_ver with actual path for jre 1_5_0_03 )
export JAVA_HOME=/path_to_jre/jre_ver
export PATH=$PATH:$JAVA_HOME/bin
make sure to clear path in ~/.bashrc
logout and login