Código:
#contenido { 
margin-right:10%; margin-left: 10%; margin-top:150px; 
} 

#izquierda { 
float: left; 
width: 134px; 
background-color:#33CC99;
z-index:9; 

} 


#derecha { 
padding-top: 1em; 
margin: 0 0 0 180px; 
background-color:#996633; 
}

<!--
body {
	background-color: #C4E1FA;
	background-image: url(../images/bg.jpg);
	margin-left: 0px;
	margin-top: 0px;
	margin-right: 0px;
	margin-bottom: 0px;
}
body,td,th {
	font-family: Arial, Helvetica, sans-serif;
	font-size: 11px;
	color: #666666;
}
.style1 {
	color: #666666;
}
.style2 {
	color: #FFFFFF;
}
.style3 {
	color: #87BBFF;
}
.style4 {
	color: #FFFFFF;
	font-weight: bold;
}
.style5 {
	color: #666666;
	font-weight: bold;
}
.style6 {
	color: #003475;
	font-weight: bold;
}
a:link {
	color: #0099ff;
	text-decoration: none;
}
a:visited {
	text-decoration: none;
	color: #0099ff;
}
a:hover {
	text-decoration: underline;
	color: #00ccff;
}
a:active {
	text-decoration: none;
	color: #0099ff;
}
INPUT, TEXTAREA,SELECT {
	font-size: 11px;
	font-family: Arial, Helvetica, sans-serif;
	color:333333;
	background:#EEEEEE;
}
-->