Please refer to the following code:
$('#dd').tooltip({
content: $('<div></div>'),
onUpdate: function(content){
content.panel({
width: 200,
height:200,
border: false,
href: '_content.html'
});
},
onShow: function(){
var t = $(this);
t.tooltip('tip').unbind().bind('mouseenter', function(){
t.tooltip('show');
}).bind('mouseleave', function(){
t.tooltip('hide');
});
}
});