jQuery(document).ready(function($) {    
    $("#push").hide();
    $("#mainNav").hover(
        function() {
            $("#push").slideDown("fast");
            shouldclose = false;
        },
        function() {
            setTimeout("checkSlideUp()", 250);
            shouldclose = true;
        }
    );
    $("#push").hover(
        function() {
            $("#push").slideDown("fast");
            shouldclose = false;
        },
        function() {
            setTimeout("checkSlideUp()", 250);
            shouldclose = true;
        }
    );
});

function checkSlideUp() {
    if (shouldclose) {
        jQuery("#push").slideUp("fast");
    }
}