contract Ownable {
  address public owner;
  bool public running = true;


  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  event StopTransaction(address indexed owner);
  event StartTransaction(address indexed owner);


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function Ownable() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  modifier onlyRunning() {
    require(running == true);
    _;
  }
  
  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */
  function transferOwnership(address newOwner) public onlyOwner {
    require(newOwner != address(0));
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }
  

  function stopTransaction() public onlyOwner {
    running = false;
    emit StopTransaction(msg.sender);
  }

  function startTransaction() public onlyOwner {
    running = true;
    emit StartTransaction(msg.sender);
  }
}
/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
function transferOwnership(address newOwner) public onlyOwner {
    require(newOwner != address(0));
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }
/**
 * @dev Allows the current owner to transfer control of the contract to a newOwner.
 * @param newOwner The address to transfer ownership to.
 */