HTML and CSS Reference
In-Depth Information
Scripts are used for a wide variety of purposes. The following list describes some of
the more popular uses of scripts and how to modify them for accessibility:
•
Pull-down menus
: Many Web designers use scripts to save screen space by inserting
pull-down menus containing links to other pages in the site. Pull-down menus are usu-
ally accessed with a mouse. To assist users who cannot manipulate a mouse, include
keyboard shortcuts to all pull-down menus. In addition, the links in a pull-down menu
should be repeated elsewhere on the page or on the site in a text format.
•
Image rollovers
: Image rollovers are used to highlight linked elements. However, since
image rollovers rely on the ability to use a mouse, pages should be designed so that roll-
over effects are not essential for navigating a site or for understanding a page's content.
•
Dynamic content
: Scripts can be used to insert new text and page content. Because
some browsers designed for users with disabilities have scripting turned off by default,
you should either not include any crucial content in dynamic text, or you should pro-
vide an alternate method for users with disabilities to access that information.
Applets and plug-ins are programs external to a Web page or browser that add special
features to a Web site. The Section 508 guideline for applets and plug-ins is
§1194.22 (m) When a Web page requires that an applet, plug-in or other application
be present on the client system to interpret page content, the page must
provide a link to a plug-in or applet that complies with §1994.21(a)
through (i).
This guideline means that any applet or plug-in used with your Web site must be com-
pliant with sections §1994.21(a) through (i) of the Section 508 accessibility law, which
deal with accessibility issues for software applications and operating systems. If the
default applet or plug-in does not comply with Section 508, you need to provide a link
to a version of that applet or plug-in which does. For example, a Web page containing
a Real Audio clip should have a link to a source for the necessary player. This places the
responsibility on the Web page designer to know that a compliant application is avail-
able before requiring the clip to work with the page.
Web Forms
The Section 508 standard for Web page forms states that
§1194.22 (n) When electronic forms are designed to be completed on-line, the form
shall allow people using assistive technology to access the information,
fi eld elements, and functionality required for completion and submis-
sion of the form, including all directions and cues.
This is a general statement that instructs designers to make forms accessible, but it
doesn't supply any specifi c instructions. The following techniques can help you make
Web forms that comply with Section 508:
•
Push buttons
should always include value attributes. The value attribute contains the
text displayed on a button, and is rendered by different types of assistive technology.
•
Image buttons
should always include alternate text that can be rendered by nonvisual
browsers.
•
Labels
should be associated with any input box, text area box, option button, check-
box, or selection list. The labels should be placed in close proximity to the input fi eld
and should be linked to the fi eld using the label element.
•
Input boxes
and
text area boxes
should, when appropriate, include either default text
or a prompt that indicates to the user what text to enter into the input box.
•
Interactive form elements
should be triggered by either the mouse or the keyboard.
