So I got the objective system planned and some of it scripted and the problem is when I want a character to say something which depends on this how many players are there. I tried if(ugxm_players==1){ *chunk of code* } and it says variable ugxm_players not initialised. I need help with that.

Well is that variable initialized? If I needed to check something like that I would do:

players = GetPlayers();
if(players.size == 1)
{
/*code*/
}