The technique of realizing the sliding _javascript of div layer following scroll bar based on JavaScript

In a page to put 2 floating box, the hover box with the page scroll up and down the effect of fluctuation, and finally fixed in the same position

The effect is shown as follows:

The code is as follows:

<! DOCTYPE html>  

Here to share a piece of code page at the top of the fixed Div, do not move with the scroll bar, prompting browser information

Example 1:

Example 2:

<style type= "Text/css" >
{
margin:0px;
padding:0px;
}
Body {
background-attachment:fixed/* Prevent screen flash in IE6/
}
#topNavWrapper {
width:100%;
   text-align:left;
height:28px;
margin:0px Auto;
z-index:100;
_position:relative;
_top:0px;
}
#topNav {
width:100%;
Float:left;
Display:block;
z-index:100;
overflow:visible;
position:fixed;
top:0px; /* Position fixed for IE6 * *
_position:absolute;
_top:expression (documentelement.scrolltop + "px");
height:28px;
}
</style>