Dim background elements when displaying submenu I am developing a site with Drupal 7 and the requirement that I need to implement is that when a sub-menu is being displayed from the main navigation bar, the rest of the site (all the elements behind the sub-menu) is dimmed (just like when displaying a modal dialog box with JQuery). 

I was wonder how I would go about accomplishing the same effect using Drupal's default menu system?

Thanks.
There's a bunch of options.  jQuery is probably the easiest but I could envision a way of doing it with CSS only using some combination of clever sibling and pseudo-class selectors.  You could also do it using an overlay element and some z-index work. Or just use JS/jQuery to dim the other element's opacity either using animate or adding a class that has an opacity transition.  The best choice depends on your requirements and how your HTML is structured.

But the question is a little vague and not particularly Drupal related.  If you want do the last case above, just do on('hover', function() ) {} and set the opacity / class of the elements to dim.