Simple modal box as seen on http://stackoverflow.com/a/11090278

simple-modal.css

/**
 * White
 *
 */

#modal-background {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: white; /* << change this for black */
    opacity: .50;
    -webkit-opacity: .5;
    -moz-opacity: .5;
    filter: alpha(opacity=50);
    z-index: 1000;
}

#modal-content {
    background-color: whitesmoke; /* << change this for black */
    display: none;
    height: 480px;
    width: 640px;
    margin: -240px 0 0 -320px; /* << margins = half width and height */
    padding: 10px;
    position: absolute;
    top: 50%;
    left: 50%;
    z-index: 1000;
}

#modal-background.active, #modal-content.active {
    display: block;
}​

simple-modal.html

<button id="modal-launcher">Launch Modal Window</button>

<div id="modal-background"></div>
<div id="modal-content">
    <button id="modal-close">Close Modal Window</button>
</div>​

simple-modal.js

$(function(){
    $("#modal-launcher, #modal-background, #modal-close").click(function() {
        $("#modal-content, #modal-background").toggleClass("active");
    });
});