Someone

on 1:join:#:{ 
if (%greet. [ $+ [ $nick ] $+ ] ) { msg $chan « $nick » %greet. [ $+ [ $nick ] ] } }

alias delgreet { unset %greet. [ $+ [ $1 ] ] $2- | echo -a Removed Greet From $1 }
alias greet { set %greet. [ $+ [ $1 ] ] $2- | echo -a Added Greet For $1 }