Cara fix mysqli_fetch_row() expects parameter 1 to be mysqli_result, bool given gmna?

mohon bantuannya gan..

    <?php
        $conn = new mysqli('localhost', 'root', '');
        mysqli_select_db($conn, 'employeedb');
        if (isset($_GET['username']) && $_GET['username'] != '' &&
        	isset($_GET['password']) && $_GET['password'] != '')
        {
            $email = $_GET['username'];
            $password = $_GET['password'];

            $getData = "SELECT 'ur_Id','ur_username','ur_password' FROM 'tbl_user' WHERE 'ur_username'='" .$email."'
            and 'ur_password'='".$password."'";

            $result = mysqli_query($conn,$getData);

            $userId="";
            while($r=mysqli_fetch_row($result)) //bagian yang salah
        		{
            	$userId=$r[0];
        		}

            if ($result && $result->num_rows > 0 ){

                $resp["status"] = "1";
                $resp["userid"] = $userId;
                $resp["message"] = "Login successfully";
            }
            else{
                $resp["status"] = "-2";
                $resp["message"] = "Enter correct username or password";
            }

        }
        else
        {

            $resp["status"] = "-2";
            $resp["message"] = "Enter Correct username.";


        }


        @mysqli_close($conn);

    ?>