function start( uint256 _startTimestamp, uint256 _endTimestamp, address _fundingAddress ) public onlyManager() hasntStarted() hasntStopped() {
		require(_fundingAddress != address(0));
		require(_startTimestamp >= block.timestamp);
		require(_endTimestamp > _startTimestamp);
		duration = _endTimestamp - _startTimestamp;
		require(duration >= MIN_CROWDSALE_TIME && duration <= MAX_CROWDSALE_TIME);
		startTimestamp = _startTimestamp;
		endTimestamp = _endTimestamp;
		started = true;
		emit CROWDSALE_START(_startTimestamp, _endTimestamp, _fundingAddress);
	}