jquery - 为什么我的 jQuery Dropdown 效果会跳动？

Question

我为我制作的下拉导航制作的 jQuery 非常跳跃而且不是很流畅。有人可以看看下面的 jQuery 并告诉我我可以做些什么来修改它并使其尽可能平滑吗？

谢谢

    jQuery.noConflict();

var time = 0;

jQuery(document).ready(function () {
    // mouseenter
    jQuery('ul.scmegamenulist li.scmegamenumain').mouseenter(
        function openmenu() {

            // slideDown / fadeIn / show
            if(<?php echo Mage::getStoreConfig('megamenu/jquery/enable',Mage::app()->getStore()); ?> == 1){
                var openeffect  = <?php echo Mage::getStoreConfig('megamenu/jquery/open',Mage::app()->getStore()); ?>;
                var opentime    = <?php echo Mage::getStoreConfig('megamenu/jquery/opentime',Mage::app()->getStore()); ?>;

                if(openeffect       == 1){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).hide().delay(time).fadeIn(opentime);
                }else if(openeffect == 2){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).hide().delay(time).slideDown(opentime);
                }
                else if(openeffect  == 3){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).hide().show();
                }
                else if(openeffect  == 4){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).hide().delay(time).show(opentime);
                }
            }
        }
    );

    // mouseleave
    jQuery('ul.scmegamenulist li.scmegamenumain').mouseleave(
        function closemenu() {

            // slideUp / fadeOut / hide
            if(<?php echo Mage::getStoreConfig('megamenu/jquery/enable',Mage::app()->getStore()); ?> == 1){
                var closeeffect = <?php echo Mage::getStoreConfig('megamenu/jquery/close',Mage::app()->getStore()); ?>;
                var closetime   = <?php echo Mage::getStoreConfig('megamenu/jquery/opentime',Mage::app()->getStore()); ?>;

                if(closeeffect          == 1){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).show().fadeOut(closetime);
                    time = closetime;
                }else if(closeeffect    == 2){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).show().slideUp(closetime);
                    time = closetime;
                }else if(closeeffect    == 3){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).show().hide();
                    time = 0;
                }else if(closeeffect    == 4){
                    jQuery(this).children('div.scmegamenusub').stop(true, true).show().hide(closetime);
                    time = closetime;
                }
            }
        }
    );
});