今天在网站上的一个广告网站看到的一jquery特效，感觉不错，也许以后有用，就记录了下来！
正常情况下： 
访问情况：
拖动了一下：
//浮动导航条的拖动与展开收缩
$(function () {
var box = $('.menu'),
obj = box.children('span');
obj.show();
box.hover(function () {//鼠标移上去后出现选择菜单
obj.stop(false, true).show(300);
}, function () {
obj.stop(false, true).hide(150);
})
var box = document.getElementById('menu');
box.onmousedown = function (event) {
var e = event || window.event,
t = e.target || e.srcElement,
x1 = e.clientX,
y1 = e.clientY,
dragLeft = this.offsetLeft,
dragTop = this.offsetTop;
document.onmousemove = function (event) {
var e = event || window.event,
t = e.target || e.srcElement,
x2 = e.clientX,
y2 = e.clientY,
x = x2 - x1,
y = y2 - y1;
box.style.left = (dragLeft + x) + 'px';
box.style.top = (dragTop + y) + 'px';
}
document.onmouseup = function () {
this.onmousemove = null;
}
}
})