You can easy get that effect without using jQueryUI, for example:
$(document).ready(function(){
$('#slide').click(function(){
var hidden = $('.hidden');
if (hidden.hasClass('visible')){
hidden.animate({"left":"-1000px"}, "slow").removeClass('visible');
} else {
hidden.animate({"left":"0px"}, "slow").addClass('visible');
}
});
});
Try this working Fiddle:
http://jsfiddle.net/ZQTFq/