Ne pas mettre de menu "XHTML"

<div id="menu">
	<ul>
		<li><a href="look.htm">HOME</a></li>
		<li><a href="constructions.htm">DOWNLOAD</a></li>
		<li><a href="faqs.html">FAQs</a></li>
		<li><a href="divers.htm">PARTENAIRES</a></li>
		<li><a href="index.htm">CONTACT</a></li>
	</ul>
</div>
<div id="sous-menu">
	<ul>
		<li><a href="salon.htm">salon</a></li>
		<li><a href="chambre.htm">chambre</a></li>
		<li><a href="cuisine.html">cuisine</a></li>
		<li><a href="sam.htm">salle à manger</a></li>
		[...]
	</ul>
</div>
<div id="content">

</div>

body
{
background-image: url("images/fond.jpeg");
width: -30px; /* indique la largeur de ton site */
margin-left: auto;
margin-right: auto;
background-color: #202020;
font-family:"Times New Roman", Arial, Times, sans-serif; /* serif ou sans-serif il faudrait choisir !!! */
}

a
{
color: #772300;
text-decoration: none;
}

a:hover
{
color: #929189;
}

#en_tete
{
/* width: 855px; */
height: 159px;
/* margin-left: 79px; */
/* margin-top: 20px; */
border: 2px ridge #929189;
background: url("images/logo_simsdesign.jpg") center no-repeat;
}
#menu
{
width: 100%;
/* float: center */
text-align:center;
}
/* +++ */
ul
{
margin:0;
padding:0;
}
/* +++ */
li
{
font-size: large;
/*  margin-right: auto; */
margin-top: 10px;
float: left;
background-color: none;
color: white;
list-style-type: none;
}
/* +++ */
div#sous-menu
{
width:160px;
float:left;
}
/* +++ */
#content
{
/* width: 815px; */
height: 450px;
/* +++ */
margin-left: 160px; 
/* +++ */
/* margin-left: 79px; */
/* margin-top: -2px; */
padding: 20px;
background-color: white;
color: black;
text-align: justify;
border: 2px ridge #929189;
}

#pied_de_page
{
/* width: 900px; */
clear: left;
margin-top: 200px;
color: white;
text-align: center;
}
h4
{
/* text-align: right; */
font-family: Ariel; /* excellent !!! */
font-size: 20px;
text-align: center;
font-style: normal;
}