With code below you can click all you want...(I didn't used Jquery UI for this but good ol Jquery library, but it should work with UI...)
Try this:
Fiddle here
$(document).ready(function(){
$('.button').click(function(){
if($('.toggle').is(':visible')){
$('.toggle').slideUp(500);
}
else{
$('.toggle').slideDown(500);
}
});
});