/getpos [playerid] HELP

Why doesnt this work?

if(strcmp(cmd, "/getpos", true) == 0)
	{
	if(IsAdmin == 1)
	{
	new PlayerID;
	new tmp[256];
	tmp = strtok(cmdtext, idx);
	
	if(!strlen(tmp))
	{
	SendClientMessage(playerid, COLOR_YELLOW, "USAGE: /getpos [playerid]");
	return 1;
	}
	PlayerID = strval(tmp);
	
	new gpp = GetPlayerPos(PlayerID, x, y, z);
	new str[256];
	format(str, sizeof(str), "%s", gpp);
	SendClientMessage(playerid, COLOR_WHITE, str);
	}
	else
	{
	SendClientMessage(playerid, COLOR_RED, "You are not an admin!");
	}
	return 1;
	}


HELP!!!