[jQuery] Accordion Mouseover Event

Hello,
I am trying to implement an accordion with event = "mouseover",

when I write
$(function() {
$("#accordion").accordion({
event: "mouseover"
});
});

It shows the accordion and I can navigate by mouseover,
but , when I write it
$(function() {
$("#accordion").accordion();
});
here the default is "click"

and I create a new button which changes the event value
to :"mouseover"
function onMouseOverAccordionFn(){

$('#accordion').accordion('option', 'event', 'mouseover');
alert($('#accordion').accordion('option', 'event'));
}

after clicking the button, the alert arise and tells that the new
"event" value is "mouseover"
but, the accordion still needs a click to be navigated!!

Help please.