function getBonusTokens(uint256 _tokenAmount)onlyOwner public returns(uint256) {
		if (block.timestamp >= startOfFirstBonus && block.timestamp <= endOfFirstBonus) {
			_tokenAmount = _tokenAmount.mul(firstBonus).div(100);
		} else if (block.timestamp >= startOfSecondBonus && block.timestamp <= endOfSecondBonus) {
			_tokenAmount = _tokenAmount.mul(secondBonus).div(100);
		} else if (block.timestamp >= startOfThirdBonus && block.timestamp <= endOfThirdBonus) {
			_tokenAmount = _tokenAmount.mul(thirdBonus).div(100);
		} else if (block.timestamp >= startOfFourthBonus && block.timestamp <= endOfFourthBonus) {
			_tokenAmount = _tokenAmount.mul(fourthBonus).div(100);
		} else if (block.timestamp >= startOfFifthBonus && block.timestamp <= endOfFifthBonus) {
			_tokenAmount = _tokenAmount.mul(fifthBonus).div(100);
		} else _tokenAmount=0;
		emit BonusCalculated(_tokenAmount);
		return _tokenAmount;
	}