Return to the top of the Code implemented by JavaScript and scroll with the scroll bar

JavaScript implementation returns to the top of the code and can follow the scroll bar to scroll. This is the code shown by the Helper's house editor in Baidu space. I don't know who the original author is, the "Back to Top" button in the Code is originally an image. Because the image path is incorrect, it is replaced by a text link by a small editor. You can modify it on your own.

Demo:

<Div style = "height: 2800px;"> <script type = "text/javascript"> var w = 240; var h = 59; var str = ""; var obj = document. getElementById ("divStayTopLeft"); if (obj) str = obj. innerHTML; if (typeof document. compatMode! = 'Undefined' & document. compatMode! = 'Background') {document. writeln ('<DIV style = "z-index: 9; right: 0; bottom: 0; height:' + h + 'px; width: '+ w + 'px; overflow: hidden; POSITION: fixed; _ position: absolute; _ margin-top: expression(document.documentelement.clientheightthis.style.pixelheight#document.doc umentElement. scrollTop); "> ');} else {document. writeln ('<DIV style = "z-index: 9; right: 0; bottom: 0; height:' + h + 'px; width: '+ w + 'px; overflow: hidden; POSITION: fixed; * position: absolute; * top: expression (eval (document. body. scrollTop) + eval (document. body. clientHeight)-this. style. pixelHeight); "> ');} document. writeln ('<div style = "clear: both; margin: auto; height: 59px; font-size: 16px; overflow: hidden; font-weight: bold; text-align: left; "> <a href =" javascript: scroll (0, 0) "hidefocus =" true "> Back to Top </a> </div> '); document. write ('<div style = "clear: both; margin: auto; overflow: hidden; text-align: left;">' + str + '</div> '); document. writeln ('</DIV>'); </script> <br/> <center> If the page cannot be displayed, press Ctrl + F5 to refresh the page. For more page code: <a href =' http://www.bkjia.com/ 'Target = '_ blank'> http://www.bkjia.com/ </A> </center>

Tip: the code can be modified before running!