pragma solidity ^0.4.13;

contract SimpleAuction {
	uint auctionEnd;
	address public highestBidder;
	uint public highestBid;
	address beneficiary;

	// Allowed withdrawals of previous bids
	mapping(address => uint) pendingReturns;

	// Set to true at the end, disallows any change
	bool ended;

	// Events that will be fired on changes.
	event HighestBidIncreased(address bidder, uint amount);
	event AuctionEnded(address winner, uint amount);

	function SimpleAuction (uint _biddingTime, address _beneficiary) public {
		beneficiary = _beneficiary;
		auctionEnd = now + _biddingTime;
	}

	function bid() payable {
		require (msg.value > highestBid);
		if (highestBidder != 0) {
			pendingReturns[highestBidder] =	pendingReturns[highestBidder]+highestBid;
		}
	highestBidder = msg.sender;
	highestBid = msg.value;
	HighestBidIncreased(msg.sender,	msg.value);
	}

	function withdraw() public returns (bool) {
		uint amount = pendingReturns[msg.sender];
		if (amount > 0) {
			pendingReturns[msg.sender] = 0;
			if (!msg.sender.send(amount)) {
				pendingReturns[msg.sender] = amount;
				return false;
			}
		}
		return true;
	}

	function getFunds() constant public returns(uint) {
		return this.balance;
	}

	function EndAuction() public {
		// 1. Conditions
		require (!ended); // this function has already been called
		// 2. Effects
		ended = true;
		AuctionEnded(highestBidder, highestBid);
		if(!beneficiary.send(this.balance)){ }// this step will transfer the amount to beneficiary
	}
}