Quick Introduction to HTML
A web page form allows the user to send information to a special program on a web server computer.
Although it is relatively easy to write the HTML that describes the form in the web page, the program to which it communicates must either be written by a computer programmer, or bought. In any case, the program is not part of HTML. This page will describe only the HTML part of implementing a working web form.
The HTML of a form consists of a
form tag enclosing tags
for various form controls, including text entry fields, various
buttons, a file selection control, and menus. (You are probably
familiar with all of these from pages you have visited.)
The user types in the text fields, clicks on the buttons and selects
items from the menus.
Finally, the user submits the form, usually by clicking on a special
The exact action that follows from submission is specified by the
form tag. Generally, the user’s browser gathers the
settings from all the controls in the form, and sends the collected
information to the site specified by the
then waits for the server to respond. The response is in the form
of a new HTML document, which the browser then displays to the user.
A single web page may contain multiple forms. However, the information that is submitted to the server comes from the form whose “submit” button was clicked.
By combining a form with a script, you can very much improve the user’s experience.
One common use of a script is a field preverify. The idea is to check the correctness of information provided by the user and alert them of any problems, before they submit the form.
A cookie is a small bit of information stored by the web browser on behalf of a specific web site. When the user again looks at the web site, the cookie is sent back to the web site. The cookie is only sent back to the web site of its origin.
Unless further steps are taken, the information in a form is transmitted over the Internet as plain text. Such information is very easily intercepted, and could be used against the user.
Modern servers and browsers facilitate encrypted (or coded) communications for just this sort of information.
The communications Internet service HTTP is by definition in plain text,
but that of the service HTTPS is encrypted. To make sure a link to a
document is encrypted, put in the link’s URL the service