I'd love to know how to do that too.
It'd be nice if you have multiple drop downs and content next one depends on the previous.
For example:
I have 1 drop down visible with options: Computer issues, Printer Issues, Network issues.
When I select "Computer Issues", 2nd level drop down appears beside it with options: "Operating System", "Software Problem", "Hardware Problem", "Other".
When I click on "Software Problem", I'd get 3rd level drop down with options: "Outlook", "Microsoft Office", "MAC Office", "other"....
This would really help to nerrow down the issue.
Also, on one ticketing system, I saw a window with various solutions from Knowledge Base on the side that relate to selected topic. Solutions also could be filtered using the Topics selected on each level. This would prove benficial for any Help desk since Customer could find resolution on his own by nerrowing down the issue and obtaining answer(s) in Solution window.
Less tickets - less work. There is a return on investment for any business.