CT218 lab3
http://www.it.nuigalway.ie/~gettrick/courses/CT218/labs/l3.html
This week you will be creating a telephone book application. The GUI should resemble the following (2 text boxes, 2 list boxes, 3 command buttons):

When the Add button is clicked, the name is added to the list of names, and the number is added to the list of numbers. If either the name or the number text box is empty, however, the lists should not be added to.
Since the names and numbers are stored in two separate list boxes, it is important that the program ensures that if a name is clicked on (highlighted), then the correct phone number is automatically highlighted too. This should also work in reverse, i.e. if the user clicks on a number, the correct name should be highlighted.
The Search button should use an InputBox to request a name to search for. If the name appears in the list, it should be highlighted. If the name doesn't appear, the user should be alerted to this fact.
The Exit button should end the program.

