contract ERC20 {
    // Get the total token supply
    uint public totalSupply;
    // Get the account balance of another account with address _owner
    function balanceOf(address who) constant returns(uint256);
    // Send _value amount of tokens to address _to
    function transfer(address to, uint value) returns(bool ok);
    // Send _value amount of tokens from address _from to address _to
    function transferFrom(address from, address to, uint value) returns(bool ok);
    // Allow _spender to withdraw from your account, multiple times, up to the _value amount.
    // If this function is called again it overwrites the current allowance with _value.
    // this function is required for some DEX functionality
    function approve(address spender, uint value) returns(bool ok);
    // Returns the amount which _spender is still allowed to withdraw from _owner
    function allowance(address owner, address spender) constant returns(uint);
    // Triggered when tokens are transferred.
    event Transfer(address indexed from, address indexed to, uint value);
    // Triggered whenever approve(address _spender, uint256 _value) is called.
    event Approval(address indexed owner, address indexed spender, uint value);

}
// ERC Token Standard #20 Interface 
function approve(address spender, uint value) returns(bool ok);
// Allow _spender to withdraw from your account, multiple times, up to the _value amount.
// If this function is called again it overwrites the current allowance with _value.
// this function is required for some DEX functionality