simplebank.sol

pragma solidity ^0.4.24;

contract SimpleBank {

    mapping (address => uint) private balances;
	
    event LogDepositMade(address accountAddress, uint amount);
	
    address public owner;

    constructor() public {
        owner = msg.sender;
    }		

    function deposit() public payable returns (uint) {	       

        balances[msg.sender] += msg.value;

        emit LogDepositMade(msg.sender, msg.value);

        return balances[msg.sender];
    }

    function balance() constant public returns (uint) {
        return balances[msg.sender];
    }
}