[Kar]

pawn Код:

public Smoking(playerid)
{
    new Float:fHealth;
    new string[180];
    GetPlayerHealth(playerid, fHealth);
    if (fHealth < 75.00)
    {
        format(string, sizeof(string), "* %s taps on his cigarrete and finishes it off", GetPlayerNameEx(playerid));
        ProxDetector(20.0, playerid, string, COLOR_PURPLE,COLOR_PURPLE,COLOR_PURPLE,COLOR_PURPLE,COLOR_PURPLE);
        IsSmoking[playerid] = 0;
        SetPlayerHealth(playerid, fHealth+25);
    }
    else
    {
        SendClientMessage(playerid, COLOR_RED, "[Info:] You're health is so good that the cigarrette damages it!");
        SetPlayerHealth(playerid, fHealth+10);
        IsSmoking[playerid] = 0;
    }
    return 1;
}

your new float didnt have cap F.