Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.5.13+commit.5b0b510c.js&optimize=false&runs=200&gist=

contracts...Owned.sol

pragma solidity ^0.5.11;

contract Owned {
    address owner;
    
    constructor() public {
        owner = msg.sender;
    }
    
    modifier onlyOwner() {
        require(msg.sender == owner, "You are not allowed");
        _;
    }
}