HTML/CSS “Pop-Up” Window and Disabled Background

Question

This is a silly question since I can\'t find the right keywords to use to get the answer by searching Google, unfortunately.

You know when you click a link and the b

Answer 1

it's done by creating an overlaying div on the fly in JS, like:

var gab = document.createElement('div');
  gab.setAttribute('id', 'OVER');
  gab.innerHTML='
hello
';
  document.body.appendChild(gab);

use a CSS class like

#OVER{width:100%; height:100%; left:0;/*IE*/ top:0; text-align:center; z-index:5; position:fixed; background-color:#fff;}
.overlay {width:100%; z-index:6; left:0;/*IE*/ top:30%; font-color:#cdcdcd; font-size:0.8em; text-align:center; position:fixed; background-color:#000;}

dunno how it's called ..