encountered Web sites that require you to register for their services by providing personal information. Basic information, such as a username and password, are generally necessary to identify you in the Web site's network. However, Web site operators like extended registration because it allows them to learn more about you, which helps them deliver advertising more closely matched to your interests. (As charitable as that sounds, the endgame, of course, is getting you to click the advertisements.) Registration probably isn't as rosy from your perspective. It requires you to enter the same information - such as ZIP code - again and again across multiple sites, and it forces you to remember the login information you use at each Web site. Repetitive tasks and long-term memory - isn't that what computers were supposed to help you with? Firefox comes to the rescue with two handy features: Automatic form filling: Enter a piece of information once, and Firefox helps you fill it in again in the future. Automatic login filling: This feature remembers your username/password combinations at Web sites that require you to log in. I give you the details about both of these features in this chapter.           Saving Your Sanity with Saved Forms By default, Firefox automatically saves information you enter into online forms, such as search phrases, addresses, and ZIP codes. When you begin typing the same information into another form, Firefox automatically suggests your previous entries in a list below the form, as shown in Figure 8-1. To see the complete list of suggestions without beginning to type, double-click within the empty form field or press the down-arrow key. If no suggestions are available, either you haven't entered the information previously, or Firefox can't understand what the field is asking for (as I describe a little later). To select a suggestion, click it or navigate to it with the down-arrow key and press Enter. Figure 8-1: Registering for an eBay account takes just a few seconds thanks to automatic form filling. TECHNICAL STUFF Firefox compares apples to apples when it makes form suggestions. For example, if your address starts with 3 and your telephone number starts with 3, Firefox won't suggest your address when you begin typing your telephone number. In general, this feature is convenient because it cuts down on silly suggestions and helps you choose the right one faster. However, it also requires that Firefox understand exactly what a form field is asking for, so it knows which of your previous entries to suggest. This is easier said than done because Web sites refer to the same piece of information (for example, a telephone number) differently (as in "phone number," "phone," "phone #," "home number," and so on). Firefox uses advanced algorithms to understand forms and make appropriate suggestions.