error 021: symbol already defined: "ReturnUser"

ReturnUser(text[]) {

	new
		strPos,
		returnID = 0,
		bool: isnum = true;

	while(text[strPos]) {
		if(isnum) {
			if ('0' <= text[strPos] <= '9') returnID = (returnID * 10) + (text[strPos] - '0');
			else isnum = false;
		}
		strPos++;
	}
	if (isnum) {
		if(IsPlayerConnected(returnID)) return returnID;
	}
	else {

		new
			sz_playerName[MAX_PLAYER_NAME];

		foreach(new i: Player) {
			GetPlayerName(i, sz_playerName, MAX_PLAYER_NAME);
			if(!strcmp(sz_playerName, text, true, strPos)) return i;
		}
	}
	return INVALID_PLAYER_ID;
}