VB.Net problem using ComboBox calculating population growth

I need to Design a windows application and write the code that will execute according to the program requirements I have written below and Use Case Definition. I devised this requirement document.
Requirements Document
Date Submitted: April 2,2008
Application title: U.S Largest Cities Windows Application
Purpose: The windows application opens a text file with the population of the 10 largest cities in the United States. The user selects the city and displays the population for the next five years with a projected 3 % growth per year . A menu selection also can show up to 10 cities and their present population on a second Windows Form object.
Program Procedures: In a Windows application, a user can view the expected 3% population growth for the next five years for any of the 10 largest cities in the United States.
Algorithms, Processing and Conditions:
1) The user views a Windows application that contains a title, graphic, and a ComboBox object filled with the 10 largest cities in the United States. The ComboBox object is filled from a text file named cities.txt that is opened and read by the application from the USB drive (drive E: ). The text file contains each city name with the present population.
2) After the user views a Windows application from the ComboBox object, a ListBox object displays the next five years of projected population based on a 3% growth for each year for the selected city.
3) A file menu also displays the Display Present Population, Clear, and exit menu items. When the user selects the Display Present Population menu item, a second Windows form object opens and displays the current 10 largest cities and their populations.
Notes and Restrictions: 1) The user must select one city from the ComboBox object before the population of that city is displayed.(This is the part that has me very confused ComboBox.)
Comments:
1) The picture shown in the table should be selected from a picture available on the web.
2) The second Form object displays a Return to Application button to reopen the initial Form object.
Use Case Definition: The select s the city to display the expected 3% population growth.
1) The user selects the Display Present Population menu item to open a second form to display the 10 largest cities and their populations.
2) The user selects the Clear menu to clear the form.
3) The user selects Exit menu item to exit the application.
Hi it's me again I did 10 of these problems and this is another one that has me really confused.
It seem to be doing ComboBox, I get and error.
I need to zip the file.