contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  /**
  * @dev transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) {
      
    require ( balances[msg.sender] >= _value);           // Check if the sender has enough
    require (balances[_to] + _value >= balances[_to]);   // Check for overflows

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
  }
  
  // burn tokens from sender balance
  function burn(uint256 _value) {
      
    require ( balances[msg.sender] >= _value);           // Check if the sender has enough
    balances[msg.sender] = balances[msg.sender].sub(_value);
    totalSupply = totalSupply.sub(_value);
    
    Burn(msg.sender, _value);
  }
  

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) constant returns (uint256 balance) {
    return balances[_owner];
  }

}
function burn(uint256 _value) {
      
    require ( balances[msg.sender] >= _value);           // Check if the sender has enough
    balances[msg.sender] = balances[msg.sender].sub(_value);
    totalSupply = totalSupply.sub(_value);
    
    Burn(msg.sender, _value);
  }
// burn tokens from sender balance