CSS navigation bar

I’m working on a new project in which I want to make a navigation bar with CSS. So far it’s going very well and I’d say I’m ok with CSS but getting a lot better. I’m able to understand how to manipulate the menu items for the most part, but I’m struggling with making it the correct size as a whole. I’d like it to be 815 px across the web page but right now it’s a bit longer than that.

Here’s my CSS:


#container
{
    height: 100%;
    width: 815px;
    position: relative;
    text-align: left;
    margin-top: -7px;
    margin-right: auto;
    margin-bottom: 0;
    margin-left: auto;
}

#header
{
    border: 0px;
    height: 135px;
    padding: 0px;
    margin-top: 0px;
    margin-right: 0px;
    margin-bottom: 0px;
    margin-left: 0px;
}

#navbar
{
    background-color: #66B3FF;
}

#nav
{
    width: 815px;
    border: 0px;
    margin-bottom: -1px;
    padding: 0px;
    margin-left: 0px;
    margin-right: 0px;
    margin-top: 0px;
    
}

#nav a /*LINKS IN ALL MENUES*/
{
    font-family: Verdana, Arial, Helvetica, sans-serif;
    text-decoration: none;
    color: #000000;
    font-size: 1em;
    font-weight: bold;
}

#nav li
{
    background-color: #66B3FF;
}

#nav li li a /*SUBMENU BOXES*/
{
    background-color: #66B3FF;
    display: block;
    font-weight: normal;
    font-size: .9em;
    color: #000000;
    padding: 0.2em 10px;
}

#nav li li a:hover /*SUBMENU BOX ITEMS*/
{
    background-color: #ffffff;
    padding: .2em 5px;
    border: 5px solid #cc66cc;
    border-width: 0 5px;
    color: #99cc33;
}

ul /*SUBMENU*/
{
    padding: 0;
    margin: 0;
    list-style: none;
}

li /*MENU*/
{
    float: left;
    position: relative;
    width: 135.4px;
    text-align: center;
}

li ul /*SUBMENUS*/
{
    border-left: solid 1px;
    border-right: solid 1px;
    border-bottom: solid 1px;
    display: none;
    position: absolute; 
    top: 1em;
    left: 0;
    text-align: center;
}

li > ul /*SUBMENUS*/
{
    top: auto;
    left: auto;
}

li:hover ul, li.over ul /*HOVER OVER MENU*/
{
    display: block;
}

startList = function() {
if (document.all&&document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes*;
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace(" over", "");
   }
   }
  }
 }
}
window.onload=startList;

#photos
{
    height: 550px;
    width: 815px;
    padding-bottom: 0px;
    padding-top: 0px;
    margin-top: 20px;
}
#footer
{
    background-color: #ffffff;
    margin: 0px;
    padding-top: 5px;
    padding-right: 10px;
    padding-bottom: 10px;
    padding-left: 10px;
    font-family: Geneva, Arial, Helvetica, sans-serif;
}


#footer p 
{
    margin: 0;
    padding: 2px 0;
    font-size:0.7em;
    font-weight:bold;
    color:#000000;
}

#footer a
{
    text-decoration:none;
    color:#000000;
}

.h1
{
    font-weight:bold;
    font-family: Arial, Helvetica, sans-serif;
    
}

a
{
    text-decoration:none
}

body {
    background-image: url(images/background_image_2.png);
    background-repeat: repeat-y;
    background-position: center;

}

.clearfloat
{
    clear:both;
    height:0;
    font-size: 1px;
    line-height: 0px;
}

my html:


<body>
    <div id="container">
        <div id="header">
            <a href=http://www.blahblahblah.com><img src="images/new_header.png" border="0" /></a>
        </div><!--HEADER-->
        <div id="navbar">
            <ul id="nav">
                <li>
                    <div><a href="">Home</a></div>
                </li>
                <li>
                    <div><a href="">Products</a></div>
                    <ul>
                        <li><a href="">Consumer</a></li>
                        <li><a href="">Professional</a></li>
                    </ul>
                </li>
                <li>
                    <div><a href="">Services</a></div>
                        <ul>
                            <li><a href="">Private Labeling</a></li>
                            <li><a href="">Custom Packaging</a></li>
                        </ul>
                </li>
                <li>
                    <div><a href="">Environment</a></div>
                </li>
                <li>
                    <div><a href="">MSDS</a></div>
                </li>
                <li>
                    <div><a href="">About Us</a></div>
                        <ul>
                            <li><a href="">History</a></li>
                            <li><a href="">Location</a></li>
                            <li><a href="">FAQ</a></li>
                            <li><a href="">News</a></li>
                            <li><a href="">Quality</a></li>
                        </ul>
                </li>
            </ul>
        </div>
        <div id="photos">FLASH</div><!--PHOTOS-->
    <div id="footer">        </div><!--FOOTER-->
    </div><!--CONTAINER-->
</body>
</html>

Thanks!