[Chris1337]

pawn Код:

public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
            if(newkeys & KEY_SECONDARY_ATTACK)
            {
             // enter script
             }
    return 1;
}

the New keys is first:

Look

pawn Код:

public OnPlayerKeyStateChange(playerid, oldkeys, newkeys)

to

pawn Код:

public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)