Escrow contract

escrow.sol

pragma solidity ^0.5.2;

contract Escrow {
    // the person who will pay the funds
    address public payer;

    // the person who will recieve funds
    address public payee;

    // the lawyer / solicitor, controller of the funds
    address public lawyer;

    constructor(address _payer, address payable _payee, uint _amount) {
        payer = _payer;
        payee = _payee;
        lawyer = msg.sender;
        amount = _amount;
    }

    function deposit() payable public {
        require(msg.sender == _payer, "sender must be the payer");
        require(address(this).balance <= amount); 
    }

    function release() public {
        require(address(this).balance == amount, "cannot release the funds until the Escrow is fully funded"); // the escrow must be 100% funded
        require(msg.sender == lawyer, "only the lawyer / controller of the escrow contract can release the funds")
        payee.transfer(amount);
    }

    function balanceOf() view public returns(uint) {
        return address(this).balance;
    }
}