Bart Simons has worked for Dr. Homer Spring for many years. Bart has been a model employee. He has not taken a vacation in over four years, always stating that work was too important. One of Bart's primary jobs at the clinic is to open mail and list the checks received. He also collects cash from patients at the cashier's window as patients leave. There are times that things are so hectic that Bart does not bother to give the patient a receipt; however, he assures them that he will make sure their account is properly credited. When things slow down at the clinic, Bart often offers to help Lisa post payments to the patients' accounts receivable ledger. Lisa is always happy to receive help since she is also quite busy and because Bart is such a careful worker.

Required 

Identify any internal control principles that may be violated in Dr. Spring's clinic.