Do not rely on scripting

Requirement: Pages must be functional with scripting disabled. Any content provided via a script must in an accessible form.

Make content generated via script accessible

Often one sees a Web page where when the user mouseovers a particular element, important information appears on the page. Often that information is presented as an image. For those using text-based browsers or those who have visual impairments, this technique is useless because they will not see the image and its information.

While there are methods that could connect a text alternative such as an alt attribute to the image, these methods are not reliable and may not be available on the user's browser. The better approach would be that rather than using an image to convey the information, use text. If an image would help convey meaning, use the text and an image. Or use the text with a link to the graphic.

General considerations about text and images

When given the choice between using straight text or incorporating text into an image, the straight text is almost always the best solution. Do not fall into the trap of using an image simply because it gives greater control over the appearance of the text.

The fundamental rule of Web development is that appearance is secondary to structure or function. The example above highlights the importance of this rule. When the developer placed more emphasis on appearance by making the text an image, he or she shut out a significant number of users from being able to access this important information.

Sticking to text to represent text will ensure faster loading of your pages, greater accessibility, search engine friendliness and a better capacity to interact with other systems.

Make sure pages function with scripting disabled

A major stumbling block for beginning developers who learn a little javascripting is to try to do too much with it. Javascript and other scripting tools such as VBScript should be considered only decoration.

Different browsers implement scripting differently. Some browsers do not support scripting at all, and several users deliberately disable scripting so that they are not bombarded by all the abuses of it.

For all these reasons, pages should be functional regardless of whether scripting is enabled or not.

Some common pitfalls to avoid are:

• Using javascript to handle your navigation
• Having content displayed through javascript pop-up windows
• Having additional menu options display when you mouse over a menu title
• Using javascript to submit a form.