Add custom message if person is already in table?

[boni.c...@gmail.com]

Hi,There

I am doing a gaming site project,so in that project I add a search box which is invite multiple player in a tournament and submitted in database but problem is when player is already exists am getting a message that is (The results could not be loaded) so i want to change this message to (Player already added in the tournament) please help if anyone know how to do it?