[Luis-]

This doesn't even compile, no doubt it is wrong.

pawn Code:

new Float:Pos[3], Float:OldPos[3], Float:NewPos[3];
    GetPlayerPos(playerid, Pos[0], Pos[1], Pos[2]);
    OldPos[0] = Pos[0];
    OldPos[1] = Pos[1];
    OldPos[2] = Pos[2];
    GetPlayerPos(playerid, NewPos[0], NewPos[1], NewPos[2]);
    if(OldPos[0] == NewPos[0]))
    {
        print("Player stopped moving");
    }

Error is: invalid expression, assumed zero.