help me

what is the problem in this?

Code:

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        if (strcmp(string, "/setrank", true) == 0)
        {
                if (orgleader[playerid] == 0)
                        return SendClientMessage2(playerid, COLOR_WHITE, "Error: You aren't the (co)leader of an organization.");
                new ID, rank[28];
                tmp = strtok(cmdtext, idx);
                if (!strlen(tmp)) return SendClientMessage2(playerid, COLOR_WHITE, "Usage: /setrank [playerid] [rank]");
                if (strlen(rank) > 28) return SendClientMessage(playerid, 0xFF0000FF,"The maximum rank length is 28 characters!");
                if (!IsPlayerConnected(ID)) return 1;
                if (GetPVarInt(giveplayerid, "playerorg") != GetPVarInt(playerid, "playerorg"))
                        return SendPlayerFormattedText(playerid, COLOR_RED, "%s is not in your organization!", giveplayer, "");
                new string[120];
                format(string,sizeof(string),"Your leader %s has given you a rank: '%s'", PlayerName(playerid), rank);
                SendClientMessage(ID, 0xFFFF00FF, string);
                format(string,sizeof(string),"You have given a rank to %s (%s)", PlayerName(playerid), rank);
                SendClientMessage(playerid, 0xFFFF00FF, string);
                return 1;
        }

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and i get this warrings

Code:

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C:\Users\Nidhal\Desktop\moi\server\gamemodes\bb_freeroam.pwn(15733) : warning 219: local variable "string" shadows a variable at a preceding level
C:\Users\Nidhal\Desktop\moi\server\gamemodes\bb_freeroam.pwn(15734) : error 017: undefined symbol "PlayerName"
C:\Users\Nidhal\Desktop\moi\server\gamemodes\bb_freeroam.pwn(15736) : error 017: undefined symbol "PlayerName"
Pawn compiler 3.2.3664                          Copyright (c) 1997-2006, ITB CompuPhase

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