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pragma solidity 0.4.20;
* @title SafeMath
* @dev Math operations with safety checks that throw on error
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
uint256 c = a * b;
assert(c / a == b);
return c;
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// assert(b > 0); // Solidity automatically throws when dividing by 0
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
contract ERC20 {
function totalSupply()public view returns (uint total_Supply);
function balanceOf(address _owner)public view returns (uint256 balance);
function allowance(address _owner, address _spender)public view returns (uint remaining);
function transferFrom(address _from, address _to, uint _amount)public returns (bool ok);
function approve(address _spender, uint _amount)public returns (bool ok);
function transfer(address _to, uint _amount)public returns (bool ok);
event Transfer(address indexed _from, address indexed _to, uint _amount);
event Approval(address indexed _owner, address indexed _spender, uint _amount);
contract FUTURE1COIN is ERC20
{using SafeMath for uint256;
string public constant symbol = "F1C";
string public constant name = "FUTURE1COIN";
uint public constant decimals = 18;
uint256 _totalSupply = 300000000 * 10 ** 18; // 300 Million Total Supply including 18 decimal
// Owner of this contract
address public owner;
// Balances for each account
mapping(address => uint256) balances;
// Owner of account approves the transfer of an amount to another account
mapping(address => mapping (address => uint256)) allowed;
// Functions with this modifier can only be executed by the owner
modifier onlyOwner() {
if (msg.sender != owner) {
// Constructor
function FUTURE1COIN () public {
owner = msg.sender;
balances[owner] = _totalSupply;
// what is the total supply of the ech tokens
function totalSupply() public view returns (uint256 total_Supply) {
total_Supply = _totalSupply;
// What is the balance of a particular account?
function balanceOf(address _owner)public view returns (uint256 balance) {
return balances[_owner];
// Transfer the balance from owner's account to another account
function transfer(address _to, uint256 _amount)public returns (bool ok) {
require( _to != 0x0);
require(balances[msg.sender] >= _amount && _amount >= 0);
balances[msg.sender] = (balances[msg.sender]).sub(_amount);
balances[_to] = (balances[_to]).add(_amount);
Transfer(msg.sender, _to, _amount);
return true;
// Send _value amount of tokens from address _from to address _to
// The transferFrom method is used for a withdraw workflow, allowing contracts to send
// tokens on your behalf, for example to "deposit" to a contract address and/or to charge
// fees in sub-currencies; the command should fail unless the _from account has
// deliberately authorized the sender of the message via some mechanism; we propose
// these standardized APIs for approval:
function transferFrom( address _from, address _to, uint256 _amount )public returns (bool ok) {
require( _to != 0x0);
require(balances[_from] >= _amount && allowed[_from][msg.sender] >= _amount && _amount >= 0);
balances[_from] = (balances[_from]).sub(_amount);
allowed[_from][msg.sender] = (allowed[_from][msg.sender]).sub(_amount);
balances[_to] = (balances[_to]).add(_amount);
Transfer(_from, _to, _amount);
return true;
// 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.
function approve(address _spender, uint256 _amount)public returns (bool ok) {
require( _spender != 0x0);
allowed[msg.sender][_spender] = _amount;
Approval(msg.sender, _spender, _amount);
return true;
function allowance(address _owner, address _spender)public view returns (uint256 remaining) {
require( _owner != 0x0 && _spender !=0x0);
return allowed[_owner][_spender];