I'm a beginner of Excel 2000 and I would like to create a drop down list on
the airfares, where different locations can be chosen, and when a location is
chosen, the cost will appear in the colums on the right.

  Expenses         Unit Cost     1 Day     2Days
1. Airfares          (here is where I need help)  
2. Hotel                  $100     $100      $200
3.Transport            $100     $100       $110
    Total                 xxx          xxx          xxx

eg. If HK-GZ is chosen, I can see the cost appears in the same row. The end
result will be getting the total sum of all the expenses.

Would it be possible to make different choices by just using one worksheet?
How can I revert to "Airfares" and make a new choice again?