Scrollbars

Using DHTML, developers can create small text areas with graphic scrollbars within a larger Web page with browser scrollbars. This Web widget allows you to create scrollable blocks of text without requiring users to scroll the entire Web page (see Figure 8).

Figure 8. Omnium Scrollbar Widget

But before you are swept away too quickly, ask yourself, why is a scrollbar necessary? Putting the content of a scrollbar in a regular HTML page poses much fewer problems for users. So what is the benefit? Before deciding to use scrollbars, consider these known usability issues:

• Scroll wheels on mice will not work as they do with browser scrollbars.
• Scrollbars might not degrade well on browsers that do not support scripts if no alternative is provided.
• Scrollbars might behave differently on Internet Explorer and Netscape. Thorough cross-browser testing is a must.
• Because space is limited in a scrollbar, users are forced to scroll to view all text.
• Some scrollbars will not resize gracefully when the browser window is resized.