help! on how to use draggable's callbacks.

help! on how to use draggable's callbacks.


I spent a day trying to make this and failed:
(well...I'm newbie with Jquery stuff)
a draggable object that alerts its position when the drag ends.
this is what I did recently.(but failed):
$(".block").draggable(
{
stop:function(ev,ui){
alert("position:" + ui.position.left + "," + ui.position.top);
}
)
//This disables the draggable object. I don't know why,but it does.
(Tried in firefox 3.0)
//And, no alerts appear
//Note:
$(".block").draggable()
worked fine.
Also, I would appreciate if someone could explain how to get the
position relative to the entire page(not the window...)