[jQuery] Drag/Drop works, but not after loading via a menu into my content div?

[[EMAIL PROTECTED]]

Hi all,
i am a beginner with javascript and finally found out how to drag the
content (a playingcard) from one div to another one.
it works when i load the page and include the content inside a content
div, but.....
Normally i have a indexpage with a content div.
I use a menu, which loads stuff in my content div like:

   $('#nav li a').click(function(){
                  if($(this).attr('href') === 'http://www.helenaweb.nl/
Klaverjassen/')
            {
               return true;
            }
            else
            {
               var ModToLoad = $(this).attr('href');
                           $("#content").load(ModToLoad);
         return false;
         }
   });

The cardgame is then loaded inside content div, but drag/drop does not
work

When i directly include the cardgame in the content div (instead of a
welcom message) the it works fine!
So, its exact the same content, because it is the same source file!

So, it does work well, but not after i load the code via my menu,
What am i doing wrong?

Thanks in advance for helping!

Peter