怎么把图片设为背景

<body background="你的图片地址"></body>

	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
	<title>CSS Flyout menus</title>
	<style>
	#nav, #nav ul {
	padding: 0;
	margin: 0;
	list-style: none;
	}
	#nav li {
	float: left;
	position: relative;
	width: 10em;
	border: 1px solid #B0C4DE;
	background-color: #E7FFF5;
	color: #2D486C;
	font: 80% Verdana, Geneva, Arial, Helvetica, sans-serif;
	margin-right: 1em;
	}
	#nav a:link, #nav a:visited {
	display: block;
	text-decoration: none;
	padding-left:1em;
	color: #2D4900;
	}
	#nav ul {
	display: none;
	position: absolute;
	padding-top: 0.5em;
	}
	#nav ul li {
	float: none;
	border: 0 none transparent;
	border-bottom: 1px solid #E7EDF5;
	background-color: #FFFFF9;
	font-size: 100%;
	margin: 0;
	margin-bottom: 0.5em;
	padding: 0;
	}
	#nav li:hover ul {
	display: block;
	}
	</style>
	</head>
	<body>
	<ul id="nav">
	<li><a href="#">Starters</a>
	<ul>
	<li><a href="#">Fish</a></li>
	<li><a href="#">Fruit</a></li>
	<li><a href="#">Soups</a></li>
	</ul>
	</li>
	<li><a href="#">Main courses</a>
	<ul>
	<li><a href="#">Meat</a></li>
	<li><a href="#">Fish</a></li>
	<li><a href="#">Vegetarian</a></li>
	</ul>
	</li>
	<li><a href="#">Desserts</a>
	<ul>
	<li><a href="#">Fruit</a></li>
	<li><a href="#">Puddings</a></li>
	<li><a href="#">Ice Creams</a></li>
	</ul>
	</li>
	</ul>
	</body>
	</html>