html, body{ 
 margin:0; 
 padding:0; 
 background: url(images/bwgrad.gif) #000000 repeat-x;
} 
 
<1-- #pagewidth{ 
	margin-bottom: 10px;
	margin-left: auto;
	margin-right: auto;
	width: 900px;
} -->

#pagewidth{
width: 90%;
margin: 10px auto;
color: #333;
line-height: 130%;
}
 
#header{
margin-top: 5px;
margin-bottom: 10px;
margin-left: auto;
margin-right: auto;
width: 75%;
height: 100%;  
color: #000000;
text-align:center;
background-color:#000000; 
border: 2px solid #5a5a5a;
} 

#left_side
{
float: left;
width: 160px;
margin: 0;
padding: 1em;
}

#right_side
{
float: right;
width: 160px;
margin: 0;
padding: 1em;
}

#nav {
border-top: 1px solid #5a5a5a;
border-bottom: 1px solid #5a5a5a;
}

#nav a {
  font-family: Trebuchet MS;
  font-weight: bold;
  margin: 10px 10px 10px 10px;

}

#nav ul{
  width:100%;
  background-color:#000000; 
  padding-left:0;
  margin:0;
}

#nav ul li{
  display:inline;
}

#nav ul li a{
  line-height: 30px;
  float:center;
  color:#FFFFFF;
  padding:6px 12px 6px 12px;
  text-decoration: none;
}

#nav ul li a:hover{

     background: #990000;
}


#content{
	color: white;
	text-align:justify;
	font-family: Trebuchet MS;
	margin-left: 10px;
	margin-right: 10px;
    margin-bottom: 10px;
}
 
#footer{
    color: #5a5a5a;
	font-size:small;
	font-family:Tahoma;
	text-align: center;
	margin-top: 2px;
	margin-left: auto;
	margin-right: auto;
	width:75%;
 	height:20px; 
 	clear:both;
 } 
 
#content img {
	border: solid #000000 5px;
}
 

.clearfix:after {
 content: "."; 
 display: block; 
height: 0; 
 clear: both; 
 visibility: hidden;
 }
 
.clearfix{display: inline-block;}

/* Hides from IE-mac \*/
* html .clearfix{height: 1%;}
.clearfix{display: block;}
/* End hide from IE-mac */