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complete list of Stupid Web Tricks.

Like most Americans, I’m geographically challenged, so much
so that it once took me an hour to find the snack bar in my hotel. The worse
part is that I’d been in the same snack bar less than 24 hours before.
Maybe that’s why I’ve got real problems dealing with Web pages that require me
to select cities and states. I usually find myself picking invalid
combinations, like putting the town of Metuchen in the state of Pennsylvania.

So I created a test page that takes into account the fact
that I could get lost going around the block. The available options are limited
based upon the client’s input. For example, if you select “Metuchen”
as the city, then “New Jersey” is automatically selected for the
state. And if the client selects the state first, then only cities valid for
that state are displayed.

This functionality is accomplished in JavaScript through the
use of the options array and the Option() constructor. The options array is
used to access the various options of an HTML select and can also be used to
remove all of a select’s options by setting the length property to 0. The option
constructor has four parameters: text, value, default selected, and selected.

That’s really all there is to it. Listing A shows the complete solution to my affliction.