NOTE: For IE usage download IE Hover Hack here: csshover.htc
Here you can see a preview of dynamic menu: goTo dynamic css menu

CSS Dynamic Menu Code

/*You need to set behavior in body so IE Hack can Work*/
body {
    font-size: 62.5%;
    font-family: ‘Lucida Grande’, Verdana, Arial, Sans-Serif;
    text-align: center;     
/*IE Hover Hack*/
    behavior:url(“csshover.htc”);
}

a:hover {
    background: yellow;
}

ul {
    margin: 0;
    padding: 0;
    display: inline;
}

ul li {
    list-style-type: none;
    position: relative;
    margin: 0;
    padding: 0;
    background: #FFE;
    width:10em;
    border: 1px solid #000;
    /*First list items float left*/
    float: left;
}

ul li a {
    display: block;
    padding: 5px 7px;
    text-decoration: none;
    background: #FFF;
}

ul li ul li {
    /*Stop floating left*/
    clear: both;
}

/*Here the hovering starts*/
ul li:hover ul {
    width: 10em;
    top: 2.3em;
    left: -0.1em;
}

ul ul, li:hover ul ul {
    display:none;
    width: 10em;
}

li:hover ul {
    display:block;
    position: absolute;
    left: 100%;
}

li:hover li:hover ul {
    display:block;
    position: absolute;
    top: -0.1em;
    left: 100%;
}

fixed

body {
    margin: 0;
    padding: 0;
    background-color: #000;
    color: #fff;
}
#page {
    margin: 0 auto;
    padding: 0;
    width: 760px;
    background: #fff;
}

click here for example Here the page never changes its size.
Try and change the size of the browser window.

fluid

body {
    margin: 0;
    padding: 0;
    background-color: #000;
    color: #fff;
}
#page {
    margin: auto;
    padding: 0;
    width: 90%;
    background: #fff;
}

click here for example Here the page always changes its size to fit to the resolution or browser window
Try and change the size of the browser window.