Sam Hill has worked for Dr. Lee Chang for several years. Sam demonstrates a loyalty that is rare among employees. He has not taken a vacation in the last three years. One of Sam's primary duties at the medical office is to open the mail and list the checks received. He also takes cash from patients at the cashier window as patients leave. At times, it is so hectic that Sam does not bother with giving patients a receipt for the cash paid on their accounts. He assures them he will see to it that they receive the proper credit. When the traffic is slow in the office Sam offers to help Mary post the payments to the patients' accounts receivable. She is always happy to receive his help, because he is a very conscientious worker.

Instructions
Identify at least five principles of internal control that may be violated in this medical office situation.