1. browser scroll bar to scroll to the top of the page
document.body.scrollTop = 0
2. The browser scroll bar to scroll to the bottom of the page
document.body.scrollTop = document.body.scrollHeight
1. browser scroll bar to scroll to the top of the page
document.body.scrollTop = 0
2. The browser scroll bar to scroll to the bottom of the page
document.body.scrollTop = document.body.scrollHeight