jQuery delay and slow down sliding speed

Question

The following code expands height of the DIV when hover function is performed and how can I change the code such that function has to take place if mouse is placed for 5 seconds. Also how can I slow down the sliding speed?

$(document).ready(function () {
    $("#myhead").hover(

    function () {
        $(this).animate({
            height: '+=250'
        }, '1000');
    }, function () {
        $(this).animate({
            height: '-=250px'
        }, '1000');
    });
});