Draw a sequence diagram on your paper, scan it, and upload it as an attachment to this question. Allowed formats are JPG, PNG, or PDF. We are designing a system that will be used by cinema visitors to buy movie tickets online. Once visitor selects a movie from the list, they select date and time when they want to see the movie. Available seats are marked as "green - available". If there are available seats visitor will be redirected to the payment page where they enter the credit card info; once they click the "Buy" button system will check the credit card validity and process the payment if everything is ok. Once the payment is done, number of available seats is decreased by one, and visitor gets an e-mail with his movie ticket at the same time. Paid seats are marked as "red - unavailable" seats. Once the payment is done, there is no option to refund the payment. One user cannot buy more than 5 tickets in one attempt. If there are no available seats for selected date and time, a proper message will be displayed to the visitor, and they will be given the option to select another date and time for the same movie. If credit card is not valid, a proper message will be displayed to the user, and they will be given an option to enter different credit card details. A cinema visitor also has an option to make a seat reservation prior to doing the final payment. In this case seats are marked as "yellow-reserved". The reservation expires if the payment is not completed within 24 hours