slide down effect with jquery

Thomas

suppose i have one div which has data. i want when i will click on a button then a new div will be created and which will cover the actual div like shutter down. here is sample code i got from a site which is very close but not the way i want.

    $(document).ready(function() {
  var $box = $('#box')
    .wrap('<div id="box-outer"></div>');
  $('#blind').click(function() {
    $box.blindToggle('slow');  
  });    
});

check the demo of above code http://www.learningjquery.com/2008/02/simple-effects-plugins
just go to site and click on blind toggle button just to see how i want the things.
i want when button will be click then a new div will be created and the new div will cover the actual div with slide down effect and when i will click again then new div will slide up.how to implement it using jquery. guide me with sample code if possible. thanks