on *:text:*:?: {
if (!$($+(%,private,$nick),2)) {
set -u100 $+(%,private,$nick) 1
msg $nick excuse me im busy...

this will send only one reply. What you do in such situation is checking if there is a variable with $nick in it. (which would exist only if you had set it) So.. if there's not a variable you set it and msg. Next time $nick messages you there will be a variable that will stop the script from replying.
P.S i've set the variable to exist for 100 seconds. After that it will reply one more time. If you want different reply each time try adding lines in a .txt file and them put them in the msg with use of $read(filename.txt)

Last edited by OrFeAsGr; 07/03/15 01:10 AM.