[JJB562]

Try this code. Just insert your random messages where I commented.

pawn Код:

// Random Messages
new RandomMSG[][] =
{
    // Insert your random messages here.
};

forward SendMSG();
public SendMSG()
{
    new randMSG = random(sizeof(RandomMSG));
    SendClientMessageToAll(COLOR_GREEN, RandomMSG[randMSG]);
}

EDIT: When you insert your random messages make sure to have quotations mark at the start and end of each of them.