pragma solidity ^0.4.4;

contract ERC20Token {

    function totalSupply() constant returns (uint256 supply) {}

    function balanceOf(address _owner) constant returns (uint256 balance) {}

    function transfer(address _to, uint256 _value) returns (bool success) {}

    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

    function approve(address _spender, uint256 _value) returns (bool success) {}

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}


contract Token is ERC20Token {

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
    uint256 public totalSupply;

    function transfer(address _to, uint256 _value) returns (bool success) {
            if (balances[msg.sender] >= _value && _value > 0) {
                balances[msg.sender] -= _value;
                balances[_to] += _value;
                Transfer(msg.sender, _to, _value);
                return true;
            } else { return false; }
        }


    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
                balances[_to] += _value;
                balances[_from] -= _value;
                allowed[_from][msg.sender] -= _value;
                Transfer(_from, _to, _value);
                return true;
            } else { return false; }
        }


    function balanceOf(address _owner) constant returns (uint256 balance) {
          return balances[_owner];
      }


      function approve(address _spender, uint256 _value) returns (bool success) {
              allowed[msg.sender][_spender] = _value;
              Approval(msg.sender, _spender, _value);
              return true;
          }

      function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
              return allowed[_owner][_spender];
          } // end of Token contract

}


contract EOS is Token {

    function () {
        //if ether is sent to this address, send it back.
        throw;
    }

    string public name;
    uint8 public decimals;
    string public symbol;

    function EOS() {
        balances[msg.sender] = 1000000000;    // creator gets all initial tokens
        totalSupply = 1000000000;             // total supply of token
        name = "EOS";               // name of token
        decimals = 0;                  // amount of decimals
        symbol = "EOS";                // symbol of token
    }

    /* Approves and then calls the receiving contract */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);

        if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }
        return true;
    }
}