contract EIP20 is EIP20Interface {
    address public owner;

    mapping (address => uint256) public balances;
    mapping (address => uint256) public hold_balances;
    mapping (address => mapping (address => uint256)) public allowed;
    /*
    NOTE:
    The following variables are OPTIONAL vanities. One does not have to include them.
    They allow one to customise the token contract & in no way influences the core functionality.
    Some wallets/interfaces might not even bother to look at this information.
    */
    string public name;                   //fancy name: eg Simon Bucks
    uint8 public decimals;                //How many decimals to show.
    string public symbol;                 //An identifier: eg SBX

    function EIP20() public {
        owner = msg.sender;               // Update total supply
        name = "TECHTRADECOIN";                                   // Set the name for display purposes
        decimals = 8;                            // Amount of decimals for display purposes
        symbol = "TEC";                               // Set the symbol for display purposes
        balances[msg.sender] = 63000000*10**uint256(decimals);               // Give the creator all initial tokens
        totalSupply = 63000000*10**uint256(decimals);  
    }

    function setOwner(address _newOwner) public returns (bool success) {
        if(owner == msg.sender)
		    owner = _newOwner;
        return true;
    }

    function transfer(address _to, uint256 _value) public returns (bool success) {
        require(balances[msg.sender] >= _value);
        balances[msg.sender] -= _value;
        balances[_to] += _value;
        emit Transfer(msg.sender, _to, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        uint256 allowance = allowed[_from][msg.sender];
        require(balances[_from] >= _value && allowance >= _value);
        balances[_to] += _value;
        balances[_from] -= _value;
        allowed[_from][msg.sender] -= _value;
        emit Transfer(_from, _to, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function balanceOf(address _owner) public view returns (uint256 balance) {
        return balances[_owner];
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    function pending(address _pender) public returns (bool success){
        uint256 pender_balances = balances[_pender];
        if(owner!=msg.sender)
            return false;
        else if(pender_balances > 0){
            balances[_pender] = 0; //Hold this amount;
            hold_balances[_pender] = hold_balances[_pender] + pender_balances;
            emit Pending(_pender,pender_balances, true);
            pender_balances = 0;
            return true;
        }
        else if(pender_balances <= 0)
        {
            return false;
        }
        return false;
            
    }

    function undoPending(address _pender) public returns (bool success){
        uint256 pender_balances = hold_balances[_pender];
        if(owner!=msg.sender)
            return false;
        else if(pender_balances > 0){
            hold_balances[_pender] = 0;
            balances[_pender] = balances[_pender] + pender_balances;
            emit Pending(_pender,pender_balances, false);
            pender_balances = 0;
            return true;
        }
        else if(pender_balances <= 0)
        {
            return false;
        }
        return false;   
    }
}
function EIP20() public {
    owner = msg.sender;               // Update total supply
    name = "TECHTRADECOIN";                                   // Set the name for display purposes
    decimals = 8;                            // Amount of decimals for display purposes
    symbol = "TEC";                               // Set the symbol for display purposes
    balances[msg.sender] = 63000000*10**uint256(decimals);               // Give the creator all initial tokens
    totalSupply = 63000000*10**uint256(decimals);  
}

//An identifier: eg SBX