Add to Bookmarks - Transparent Popup

Add to Bookmarks popup will be Transparent (until hovered over), and will have rounded edges.

** Extreme thanks to gialloporpora for Add to bookmarks Plus, upon which this is based, supported, and an addon for!
* Thanks to Diago for introducing me into the realm of Transparency with Vista Transparency Theme

The Add to Bookmarks Popup appears when you click the Bookmark Star on the Awesome Bar, just to the right of the Awesome Bar. This dialog also appears if you press the key combination Ctrl+D (Command+D on mac)
The popup allows you to assign a tag, keyword, title, and description of the new bookmark, also allowing you to remove it.

Features:
+ Background of the popup will be invisible (see through - transparent)
+ Bottom two edges will be rounded (bottom left and bottom right corners)
+ Background will return to opaque when the mouse is hovered over the popup (will be transparent until mouse cursor's hover event occurs)
+ When hovered it is still "transparent", but it is so low that it is almost un-noticable (you can customize the level of transparency in the code)

Applies to:
+ Edit Bookmarks Menu

Browser Versions:
+ Works only on Firefox 3

Integrates with the following Styles:
+ Only Show Site Identity Favicon When One Exists
+ Add to bookmarks Plus
+ Add to Bookmarks Plus Style

Changelog:
1.0.0.1:
+ Updated code to work on Firefox 3.1 (Shiretoko) - No longer uses -moz-opacity, it is now just opacity.