contract RateConfigurable is StandardCrowdsale, Ownable {

  modifier onlyBeforeStart() {
    require(now < startTime);
    _;
  }

  /**
   * @dev allow the owner to update the rate before the crowdsale starts
   * @dev in order to account for ether valuation fluctuation
   */
  function updateRate(uint256 _rate)
    onlyOwner
    onlyBeforeStart
    external
  {
    rate = _rate;
  }
}
function updateRate(uint256 _rate)
  onlyOwner
  onlyBeforeStart
  external
{
  rate = _rate;
}

/**
 * @dev allow the owner to update the rate before the crowdsale starts
 * @dev in order to account for ether valuation fluctuation
 */