#menu_sinistra{
float: left;
display: inline;
text-align: left;
width:145px;
clear: left;
}


#contenuto{
float: left;
display: inline;
text-align: left;
width:574px;
margin-left: 20px;
margin-right: 10px;
}

#menu_destra{
float: left;
text-align: center;
display: inline;
width: 220px;

}