固定在上方不动

&nbsddddddddddddddddddddddddddddddddddddddddddddddddddp;

&nbsxxxxxxxxcccccccccccccccccccxp;

?

&nbcxvcxvcxvscfgdfgxvxvcxzvcsp;

&ncxvcxzvczxvcxzvczbsp;

?

?dfdf

&nbscxzvcxzvcxzvczxvcxzp;

?

?

&nbsxzvcccccccccccccccccccccccccccccccccccccccccccccccccccp;

?

?

&nbsxcvcvvvvddddfffffffffffffffffffffffffffffffffp;

?

?

?

?

?ddddddddddddddddd

?

?

?

?

?

&nbsxp;

?

?

&nbxsp;

?

?

v

Click Here

document.documentElement.clientHeight

Click Here

Click Here

左下...

getPageScrollTop

getScrollBottom()

document.documentElement.clientHeight

document.documentElement.scrollHeight

]