Kilometerzähler nur +1 ?

public kilometerzähler3(playerid)
{
new meterstring3[128];
{
km[playerid] += DistanceLastPoint(vehicleid);
format(meterstring3,sizeof(meterstring3),"%03d Meter gefahren",km[playerid]);
SendClientMessage(playerid,0x00AFFFFF,meterstring3);
}
return 1;
}


stock DistanceLastPoint(vehicleid)
{
	new Float:xold, Float:yold, Float:zold;
	GetVehiclePos(vehicleid, xold, yold, zold);
  	return 1;
}