Popup killer automatically blocks annoying popup ad windows. A pitfall with most popup killers is that some popup windows are not ads and but they are killed by mistake. This is undesirable even with the aid of a white list. This problem is solved ideally by recoverable popup killer. Whenever a popup window is detected, it will be suppressed in a hidden state, i.e., deprived of the power to burden your eyes. Meanwhile, a toolbar icon will be flashed and you will hear an optional beep sound. If you think you may have lost a desirable popup window, just click a button to recover the last hidden popup window. The popup window will be permanently killed if it's not manually recovered after a particular time. This mechanism of popup window blocking also eliminates all script errors which are often induced by killing popup windows too early. 

$ProductName identifies popup windows by two kinds of mechanism. 

Please refer to the general page of the options dialog for options on identification mechanism.

You can also aid the popup killer with predefined filtering. Sites matching the black list will be unconditionally considered as popup windows while sites matching the white list will never be considered as popup windows.  Please refer to the section on Site Filters.

Whenever a popup window is detected, the "Block Popup" button will flash on the toolbar. Simultaneously, you will hear an optional beep sound.

When you receive the notification which indicates a popup window has been blocked and you feel you may have lost some desirable site windows, you can manually recover the last popup window by selecting "Recover Last Popup Window" from the menu or toolbar. The last-blocked popup window will be brought back immediately. No reconnection is needed.

You can also choose to recover any popup windows that haven't been permanently killed yet in the hidden sites dialog.