#leftcontent {
position: absolute;
left:10px;
top:50px;
width:200px;
}
	#centercontent {
margin-left: 199px;
margin-right:199px;
margin-left: 201px;
margin-right:201px;
} 
html>body #centercontent {
margin-left: 201px;
margin-right:201px;
}
	#rightcontent {
position: absolute;
right:10px;
top:50px;
width:200px;
background-color : blue;
}