nsIAlertsService Interface

 Displays a sliding notification window.
    
 @param imageUrl       A URL identifying the image to put in the alert.
 @param title          The title for the alert.
 @param text           The contents of the alert.
 @param textClickable  If true, causes the alert text to look like a link
                       and notifies the listener when user attempts to 
                       click the alert text.
 @param cookie         A blind cookie the alert will pass back to the 
                       consumer during the alert listener callbacks.
 @param alertListener  Used for callbacks. May be null if the caller 
                       doesn't care about callbacks.
 @param name           The name of the notification.  This is currently
                       only used on OS X with Growl.  On OS X with Growl,
                       users can disable notifications with a given name.

 @throws NS_ERROR_NOT_AVAILABLE If the notification cannot be displayed.

 The following arguments will be passed to the alertListener's observe() 
 method:
   subject - null
   topic   - "alertfinished" when the alert goes away
             "alertclickcallback" when the text is clicked
   data    - the value of the cookie parameter passed to showAlertNotification.

void showAlertNotification(in AString imageUrl, in AString title, in AString text, [optional] in boolean textClickable, [optional] in AString cookie, [optional] in nsIObserver alertListener, [optional] in AString name)