#main {  margin:0 auto;  width:900px;}

#header{
float:left;
width:900px;
}

#footer{
float:left;	
width:900px;
}

#navigation{
float:left;	
 width:150px;
}

#sidebar{
float:left;
width:150px;
}

#content{
float:left;	
 width:600px;
}