contract ERC20Interface {
    // Send _value amount of tokens to address _to
    function transfer(address _to, uint256 _value) returns (bool success);
    // Get the account balance of another account with address _owner
    function balanceOf(address _owner) constant returns (uint256 balance);
}
function balanceOf(address _owner) constant returns (uint256 balance);

// Get the account balance of another account with address _owner