function getUserTokensByGame(address user, uint32 idGame) public view returns ( string res )
	{
		res="";
		require(user!=0x0);
		for(uint256 i=0;i<totalSupply;i++) 
		{
			if (user == tokenIndexToOwner[i]) 
			{
				uint256 packed = tokens[i].option;
				uint32 idGameToken = uint32((packed >> (8*8)) & 0xFFFFFFFF);
				if (idGameToken == idGame) res = strConcat( res, ",", uint2str(i) );
			}
		}
	}