Programming instructions

6 Chapter 1 Introducing ColdFusion MX
Web browsers
A web browser is a software program residing on a computer that you use to view pages
on and navigate the World Wide Web. When you use a browser to request a page on a
website, that browser is making a web connection to a web server.
As mentioned previously, the web browser processes the web pages that it receives from a
web server and displays the pages to the user. Depending on the browser that you use and
the features it includes, you might be able to play multimedia files, view and interact with
Java applets, read your e-mail, or use other advanced features.
Some of the most popular web browsers today are Microsoft Internet Explorer, Netscape
Navigator, and Mozilla. Unfortunately, most browsers today parse web pages differently.
Web designers must pay special attention to the way a browser behaves, or users might
not see the pages as the designers intended. Therefore, web designers test their pages on
multiple browsers before publishing them on their website.
HTML
Web page authors create plain text files using the Hypertext Markup Language. This
language, known as HTML, consists of a series of simple-to-learn tags. You can use these
tags to mark up a page of text. Tags can indicate page elements, structure, formatting,
hypertext links to other locations, and so on. Web browsers read the HTML tags and
format the text and styles that appear on the computer screen.
HTML tags usually have a starting and ending tag, surrounding the text that they affect.
The starting tag turns on a feature (heading, bold, and so on), and the ending tag turns it
off. All ending tags have a forward slash (/) preceding the tag name.
Most HTML tags look like this:
<TheTagName>text</TheTagName>
The tag name is always enclosed in angle brackets (<>) and is case-insensitive, which
means that you can specify the tag name in uppercase, lowercase, or mixed case.
Most web browsers let you view the source of an HTML page. This option is usually
located in a menu or a button.
JavaScript
Web developers write JavaScript to create small programs that run in the browser.
JavaScript is one of the most popular client-side scripting languages today. It is supported
by almost all browsers on the market. Web developers use JavaScript to do these actions:
• Validate user actions.
• Create scrolling messages in a browser’s status bar.
• Animate text or images.
JavaScript can be inserted in the HTML file. HTML uses tags to mark the start and end
of the code. The <script> tag tells the browser that the following chunk of text, bounded
by the closing </script> tag, is not HTML, but rather script code to be processed.
Although using JavaScript seems much like inserting HTML content, JavaScript is more
difficult to learn than HTML. For more information about JavaScript, see any JavaScript
primer.