Keywords for Ether in Solidity Functions

contract Register is priced, owned {
    mapping (address => bool) registeredAddresses;
    uint price;

    constructor(uint initialPrice) public { price = initialPrice; }

    {
        registeredAddresses[msg.sender] = true;
    }

    function changePrice(uint _price) public onlyOwner {
        price = _price;
    }
}