You notice that your elderly dad's memory is beginning to fail. Your dad has always been very independent and insists on handling everything on his own. Unfortunately, he has forgotten to pay a bill or two. So, when you make your weekly visit, you look over his checkbook and help him reconcile his bills. Gradually you become more involved in your dad's finances and he is happy that you are now helping him to say on top of his bills. Since your dad knows you are helping him pay his bills, you begin to sign his name on the checks. Is this legal?