How can I break current action?

Hey, I wrote 2 events functions:

$('.imageItem').mouseover(function() {
$(this).fadeTo('fast', 1);
});
$('.imageItem').mouseout(function() {
$(this).fadeTo('fast', 0.8);
});

when the user mouse over on .imageItem its going 1 transparent and when he out its going 0.8 transparent, its work and everything go well, but i got problem, when im going in-out-in-out-in-out its make the effects one by one and doesnt break the current fadeTo and show the last one..