function ERC20token(uint256 _initialAmount, string _tokenName, uint8 _decimalUnits, string _tokenSymbol) public {
        totalSupply = _initialAmount * 10 ** uint256(_decimalUnits);
        balances[msg.sender] = totalSupply;
        admin = msg.sender;
        name = _tokenName;
        decimals = _decimalUnits;
        symbol = _tokenSymbol;
    }