R & A Concrete Contractors, Inc., executed a promissory note that identifies both R & A Concrete and Grover Roberts as its makers. On the reverse side of the note, the following appears: “X John Ament...

R & A Concrete Contractors, Inc., executed a promissory note that identifies both R & A Concrete and Grover Roberts as its makers. On the reverse side of the note, the following appears: “X John Ament Sec. & Treas.” National Bank of Georgia, the payee, now sues both R & A Concrete and Ament on the note. What rights does National Bank have against R & A and Ament?