nav {  
    position: absolute;  
    left: 0;  
    width: 100%;  
    background: url("nav_background.png");  
}

nav ul {  
    margin: 0 auto;  
    width: 940px;  
    list-style: none;  
} 

nav ul li {  
    float: left;  
} 

nav ul li a {  
    display: block; 
	margin-right: 10px;  
    width: 140px;  
    font-size: 14px;  
    line-height: 44px;  
    text-align: center;  
    text-decoration: none;  
    color: #777;  
}