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)  public IsWallet(_to) returns (bool) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]); 
    // SafeMath.sub will throw if there is not enough balance. 
    balances[msg.sender] = balances[msg.sender].sub(_value); 
    balances[_to] = balances[_to].add(_value); 
    emit Transfer(msg.sender, _to, _value); 
    
    return true; 
  } 

  /** 
   * @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) public constant returns (uint256 balance) { 
    return balances[_owner]; 
  }
  
  modifier IsWallet(address _address) {
		/**
		* @dev Transfer tokens from msg.sender to another address.  
		* Cannot Allows execution if the transfer to address code size is 0
		* @param _address address to check that its not a contract
		*/		
		uint codeLength;
		assembly {
            // Retrieve the size of the code on target address, this needs assembly .
            codeLength := extcodesize(_address)
        }
		require(codeLength==0);		
        _; 
   }
}
/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
function balanceOf(address _owner) public constant returns (uint256 balance) { 
    return balances[_owner]; 
  }
/** 
 * @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. 
 */