Updating a web application for usability

Your office hosts its internal asset tracking database using an ASP.NET MVC application. To find contact information for an employee from the Inventory screen, a user must exit the Inventory screen and launch a User screen. In addition, the current process takes the user to a separate login screen, but the IT department wants to be able to log in and out of the application quickly. Your IT manager wants you to update the application to improve usability. When thinking of answers to these questions, keep in mind that JavaScript alone might not be able to fix the situation.

What can you modify to enable staff to switch screens?
What can you modify to achieve quick login and logout functionality?