[YouServ]

Call the function all 1 seconds. With this script is more stable.

PHP код:

forward IsPlayerAtHiddenPackage(playerid);
public IsPlayerAtHiddenPackage(playerid)
{
    // Your script
    return 1;
}

public OnPlayerConnect(playerid)
{
    SetTimerEx("IsPlayerAtHiddenPackage", 1000, true, "i", playerid);
    return 1;
}