Section 29.4. Pop-Up Blocking

29.4. Pop-Up Blocking

Pop-up blocking was new to Windows XP Service Pack 2. Pop-ups are windows that are generated by a web page to show additional content. A legitimate use for pop-ups may be to provide a glossary term, assistance, or a product photo when users click a link on a web page. This would allow the user to stay on the same page, but gain additional information that was not deemed important enough to have screen real estate devoted to it.

Unfortunately, the legitimate uses of pop-ups are outweighed many times by the more frustrating or downright dangerous uses. Typically, pop-up technology has been used to display advertisements to users in separate windows, to open (or "spawn") additional windows when the user navigates away from a site in order to trap them on the site, or to cover parts of a dialog box so that it appears to users that they have fewer choicesfor example, to hide a part of the ActiveX consent dialog (Figure 29-3) so that only the Yes button appears rather than the No and "More info" buttons.

The issue is that there are times when the pop-up may be seen as legitimate by users, so it is important that users be aware when pop-ups have been blocked, and also have the opportunity to view the pop-up if they think that it is one they invoked. The Information Bar, discussed already in the "ActiveX Dialogs" section, provides a useful mechanism both for notifying users that a pop-up has been blocked and for giving them access to that pop-up should they choose to see it, as shown in Figure 29-10.

Figure 29-10. Information Bar showing a blocked pop-up; the bar animates down from the top of the page area, accompanied by a sound similar to tapping on a glass monitor screen

This notification occurs in the context of the user's task, but in a way that does not prevent him from continuing with his current task. In user testing, this implementation provided the best tradeoff between the ability for users to ignore unwanted pop-ups and to act on ones they wanted to see. It builds on and reinforces the use of the Information Bar for ActiveX control consent. Judging from users' positive remarks during testing and after release, this feature seems to have struck the right balance between security and convenience.