A simple fund raising contract.

donate.sol

pragma solidity ^0.4.18;

/** Simple fund raising contract */
contract Donation
{
    address beneficiary;
    uint donations;
    uint goal;
    uint amountRaised;
    
    // Authenticates contract creator
    modifier beneficiaryOnly(address _beneficiary) {
        require(msg.sender == _beneficiary);
        _;
    }
    
    // Events
    event donationSent(uint _amount, address _donator);
    event donationPeriodEnded(uint _amount);
    
    // Constructor
    function Donation (uint _goal) public  payable {
        beneficiary = msg.sender;
        donations = msg.value;
        goal = _goal;
    }
    
    // Returns the current amount of ether raised
    function getAmountRaised() public payable returns(uint) {
        amountRaised = donations;
        return(amountRaised);
    }
    
    // Returns the current goal
    function getGoal() constant public returns(uint) {
        return(goal);
    }
    
    // Returns the beneficiary of the fundraiser.
    function getBeneficiary() constant public returns(address) {
        return(beneficiary);
    }
    
    /** Send a donation */
    function sendDonation() public payable {
        require(msg.value + donations <= goal && msg.sender != address(0));
        donations += msg.value;
        
        donationSent(msg.value, msg.sender);
    }
    
    /** End the donation period without killing the contract */
    function endDonationPeriod() public payable beneficiaryOnly(beneficiary) {
            beneficiary.transfer(donations);
            amountRaised = donations;
            donations = 0;
            goal = 0;
            
            donationPeriodEnded(amountRaised);
    }
    
    /** Kill the contract */
    function killContract() public payable beneficiaryOnly(beneficiary) {
        selfdestruct(beneficiary);
    }
    
    // Fallback function
    function () public payable {
        revert();
    }
}