Dividing <DIV> into 2 part

please guide me i am newbie in CSS .... i have no idea how it is possible

 

I will write just content area code:

<style>
#content { width: 900px; overflow: hidden; }
#side1 { width: 300px; height: 700px; float: left; }
#side2 { width: 300px; height: 700px; float: left; }
#side3 { width: 300px; height: 700px; float: left; }
#half1 { width: 300px; height: 290px; margin-bottom: 10px; }
#half2 { width: 300px; height: 400px; margin-bottom: 10px; }
</style>

<div id="content">
	<div id="side1">
	
	</div>
	
	<div id="side2">
	
	</div>
	
	<div id="side3">
		<div id="half1">
			half 1
		</div>
		
		<div id="half2">
			half 2
		</div>
	</div>
</div>

Code (markup):

good luck!

 

Thanks for this code ........

 

Why not just use two separate divs?