Solidity opening application

offer.sol

pragma solidity 0.4.11;
contract Offer {
    /* Constructor */
    address public employee;
    uint public safetyDeposit;
    uint public offerStart;
    uint public lastWithdraw;
    uint public numberBlocksPerDay = 2;
    uint public ratePerDay = 0.5 ether;
    event Withdraw(address employee, uint amount, uint numberOfDay);
    event Deposit(address from, uint amount);
    modifier onlyEmployee {
        require(msg.sender == employee);
        _;
    }
    function Offer() payable {
        safetyDeposit = msg.value;
        offerStart = block.number;
        lastWithdraw = block.number;
    }
    function accept() {
        if (employee == address(0)) {
            employee = msg.sender;
        }
    }
    function withdraw() onlyEmployee {
      uint daysToWithdraw = (lastWithdraw - block.number) / numberBlocksPerDay;
      uint amountToWithdraw = daysToWithdraw * ratePerDay;
      if ((this.balance - safetyDeposit) > amountToWithdraw) {
          Withdraw(msg.sender, amountToWithdraw, daysToWithdraw);
          msg.sender.transfer(amountToWithdraw);
          lastWithdraw = block.number;
      } else {
        dismiss();
      }
    }
    function () payable {
        Deposit(msg.sender, msg.value);
    }
    function dismiss() onlyEmployee {
        selfdestruct(msg.sender);
    }
}