Here is a discussion about how to design a form for use on the web.
"Computers are supposed to make our lives easier, not more difficult. As usability-conscious designers, we can make our users' lives easier by thinking about the way people interact with our websites, providing clear direction, and then putting the burden of sorting out the details in the hands of the computers—not the users.
Use the right field for the task
Give them room to type
Shorten your forms and question "mandatory" fields
Mark mandatory fields clearly
Provide descriptive labels for all of your fields
Let the computer, not the user, handle information formatting