Create a user interface that allows users to pick the computer system of their dreams, similar in principle to the e-commerce sites selling computers over the Internet. For example, they could be given a choice of processor type, speed, memory, and hard drive size, and the option to add additional components like a DVD-ROM drive, a sound card, and so on. As the users change their selections, the price of the system should update automatically and notify them of the cost of the system as they specified it, either by using an alert box or by updating the contents of a text box.