Hello, I am trying to follow the code from this simple css drop down menu here. I have the code which I am trying to make work with what I have currently. I want the spacing between the listed items for the menu. When I use the code from the website I cannot seem to set the spacing I need.

The code I have which I want to use below but as soon as I put in everything from the simple menu it just pushes everything together. It's not exactly what I was wanting. I was hoping maybe you can help.

Code:
#header {
    
    float: left;
    
    height: 168px;
    
    width: 900px;
    
    background: #0000ff;

}

#header ul { 
    list-style-type:none;
    margin: 135px 0px 0px 8px;
}
#header li {
    float:left;
    padding: 6px 2px;  
    
}
#header ul li a {
    background:#6666FF;
    border: 1px #FFFFFF solid;
    color:#FFFFFF;
    padding: 5px 10px;
    text-decoration:none;
    font-size:0.9em;
}
HTML Code

Code:
<!DOCTYPE html>
<html>
<head>
<title>CSS Portal - Layout</title>
<!--[if IE]><script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script><![endif]-->
<link rel="stylesheet" type="text/css" href="nav.css" />
</head>
<body>

        <div id="header">
            <ul id="nav" class="drop">
            <li><a href="#">Home</a></li>
            <li><a href="#">History</a></li>
            <li><a href="#">Clients</a></li>
            <li><a href="#">Testimonials</a></li>
            <li><a href="#">Staff</a></li>
            <li><a href="#">FAQ</a></li>
            <li><a href="#">Products</a></li>
            <li><a href="#">Stock Images</a></li>
            </ul>
        </div>

</body>
</html>