title: Textbox 'popup' display on mouseover/hover for CSS/Javascript
body: <p>I have an html <code>td</code> element with text inside.  I want it so you can hover over that element, and display a textbox on top of the active page/element explaining what that td tag's content means.  Some kind of elaboration. Like the <code>&lt;abbr&gt;</code> tag.</p>
  
  <p>Can this be done in CSS or Javascript?</p>