Thanks for helping out Hector.
That is is some useful information.I was able to get back apache running also.
Before I made changes as you mentioned
Here are the entries of /etc/default/aolserver4 file
# These variables can be customized to change main AOLserver settings.
# More changes can be done by modifying the /etc/aolserver4/aolserver4.tcl Tcl script.
#
# Note that these variables are read and interpreted by the Tcl script
# too, so avoid using shell capabilities in setting vars.
#
#USER=www-data
#GROUP=www-data
#HOSTNAME=localhost
#ADDRESS=127.0.0.1
#HTTP_PORT=80
#HTTPS_PORT=443
#CONF=/etc/aolserver4/aolserver4.tcl
#RUN_DAEMON=yes
Which after your suggestion I changed to
RUN_DAEMON=no and then restarted aolserver and started Apache2
/etc/init.d/aolserver4 restart
/etc/init.d/apache2 start
Now I am able to use both AOLserver and Apache2 at the same machine.