div.dummy-container 
{	text-align:center;
	}

div.contenido {
	margin-top: 0px;
	margin-bottom: 0px;
	width:900px;	
	margin-left: auto;
	margin-right: auto;
	overflow:hidden;	
	text-align:left;
}

div.left_menu 
{
	FLOAT: left; 
	WIDTH: 175px
	}
	
div.main_content
{ 
	FLOAT: left; 
	WIDTH: 605px;
	}
	
div.center_content{
	MARGIN-TOP: 10px;
	width:590px;
	}
	
div.right_banner
{
	FLOAT: left; 
	WIDTH: 120px;	
	}