WPF Application, use switch, display a date and time, and use PasswordBox's PasswordChar property

A lab wants to install a security panel outside a laboratory room. Only authorized personnel may enter the lab, using their security codes. The following are valid security codes (also called access codes) and the groups of employees they represent:

Values Groups

1645 or 1689 Technicians

8345 Custodians

9998, 1006-1008 Scientists

Once a security code is entered, access is either granted or denied. All access attempts are written to a window below the keypad. If access is granted, the date, time and group (scientists, custodians, etc.) are written to the window. If access is denied, the date, the time, and a message, Access Denied, are written to the window. Furthermore, the user can enter any one-digit access code to summon a security guard for assistance. The date, the time and a message, Restricted Access, then are written to the window to indicate that the request has been received.

Note: For security guard assistance, you are only allowed to type a single digit (0-9) and then hit # (enter). So # key acts as enter key for all security codes. C key is used for erasing any digits typed in by mistake.

The window for the WPF should have a label, Security code: with an empty box next to it that displays input. A keypad under that. Under the keypad a label, Access log: with a textbox under the access log: label to display output.