SharePoint 2013 List Header Row Freeze

Hello, I've a long list in my site. When I scroll down then the headers are not appearing. That's why every time users should scroll-up and down. As I researched I've found a script which freezes the header row even you scroll-down. 

However, I am a very beginner in SharePoint developing. The script which I apply is below. When I apply then it doesn't make any sense. I've just changed the table id and inserted into a content editor. Can you tell me that what I'm doing wrong?

Thanks in advance.

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript"></script><style type="text/css"><!--
.DataGridFixedHeader { ; top: expression(this.offsetParent.scrollTop);}
--></style><script type="text/javascript">
$(function(){
var $table = $("TABLE[ID^='{4C9CFF20-B467-4E10-820C-0A132442CF98}']:first", "#MSO_ContentTable");<!--WRAP TABLE IN SCROLL PANE-->
$table.wrap("<DIV style='OVERFLOW: auto; HEIGHT: 420px'></DIV>");<!--FROZEN HEADER ROW-->
$("TR.ms-viewheadertr:first", $table).addClass("DataGridFixedHeader");
});</script>

KAdir