.clear{clear:both;}
#wrapper{width:800px;height:600px;}
#header{width:100%;height:100px;background:gray;}
#inner_wrapper{width:100%;height:400px;background:cyan;}
#inner_wrapper_left{width:500px;height:400px;background:yellow;float:left;}
#left_one{width:100%;height:100px;background:red;}
#left_two{width:100%;height:100px;background:pink;}
#left_three{width:100%;height:100px;background:orange;}
#left_four{width:100%;height:100px;background:blue;}
#inner_wrapper_right{width:500px;height:400px;background:brown;float:left;}
#right_one{width:100%;height:200px;background:yellow;}
#right_two{width:100%;height:200px;background:green;}
#footer{width:100%;height:100px;background:orange;}