Its an auto Lol, Brb, Ty etc. in my version, you can edit it and add more, Enjoy! :)
On *:INPUT:*:{
If ($1 == brb): { //say 12,1(_4,1Be Right Back12,1_)8,1 $2- | halt }
If ($1 == lol): { //say 12,1(_4,1Laughing Out Loud12,1_)8,1 $2- | halt }
If ($1 == ty): { //say 12,1(_4,1Thank You12,1_)8,1 $2- | halt }
If ($1 == wb): { //say 12,1(_4,1Welcome Back12,1_)8,1 $2- | halt }
If ($1 == idk): { //say 12,1(_4,1 I Don't Kknow12,1_)8,1 $2- | halt }