#section_cmds {
	border:1px solid red;
	margin:0; padding:0;
	background-color:#eee;
	}


.column_left {
	font-size:10px;
	float:left;
	background-color:blue;
	width:16em;
	overflow:hidden;
	padding:0; margin:0;
	}

.column_right {
	font-size:10px;
	float:right;
	background-color:blue;
	width:16em;
	overflow:hidden;
	padding:0; margin:0;
	}

.column_middle {
	background-color:lightblue;
	margin-left:16em;
	margin-right:16em;
	}

<div id="section_cmds" class="clearfix">
	<div class="column_left">
		<div class="skinsection">
			cmds_left
		</div>
	</div>
	<div class="column_right">
		<div class="skinsection">
			cmds_right
		</div>
	</div>
	<div class="column_middle">
		<div class="skinsection">
			cmds_content
		</div>
	</div>

</div>