CSS don't forget to clear floating clear:both_ experience Exchange

clear with empty label
. clr {clear:both;}

<div id= "Layout" >
<div id= "left" >Left</div>
<div id= "right" >Right</div>
<p class= "CLR" ></p>
</div>
using the Overflow property
#layout {overflow:auto; zoom:1;}

<div id= "Layout" >
<div id= "left" >Left</div>
<div id= "right" >Right</div>
</div>
usage: After (non IE browser)
#layout: after{
Display:block;
Clear:both; Content: "";
Visibility:hidden; height:0;
}

<div id= "Layout" >
<div id= "left" >Left</div>
<div id= "right" >Right</div>
</div> Note: Use: After need to pay attention to several points, set a height of 0 (height:0;); content is required, but its value can be null