function layout ()
{	
	function calculateSize() 
	{
		var myWidth = 0, myHeight = 0;
	  	if( typeof( window.innerWidth ) == 'number' ) 
		{
		    //Non-IE
		    myWidth = window.innerWidth;
		    myHeight = window.innerHeight;
	  	} 
		else if	( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) 
		{
	    	//IE 6+ in 'standards compliant mode'
	    	myWidth = document.documentElement.clientWidth;
	    	myHeight = document.documentElement.clientHeight;
	  	} 
		else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) 
		{
	    	//IE 4 compatible
	    	myWidth = document.body.clientWidth;
	    	myHeight = document.body.clientHeight;
	  	}
	  	
		var header_layer_height			= document.getElementById('header_layer').clientHeight;
		var main_wrapper_layer_height	= document.getElementById('main_wrapper_layer').clientHeight;
		var footer_layer_height			= document.getElementById('footer_layer').clientHeight;
		var content_height				= document.getElementById('content').clientHeight;
		
		//alert(content_height);
		
		//debugger;
		var main_wrapper_layer_new_height = myHeight - header_layer_height - footer_layer_height;
		
		
		if ( content_height > main_wrapper_layer_new_height)
		{
			var main_wrapper_layer = document.getElementById('main_wrapper_layer');
			main_wrapper_layer.style.height=String(content_height+'px');
		}
		else ( main_wrapper_layer_new_height > main_wrapper_layer_height )
		{
			var main_wrapper_layer = document.getElementById('main_wrapper_layer');
			main_wrapper_layer.style.height=String(main_wrapper_layer_new_height)+'px';			
		}	
	}
	window.onresize = calculateSize;
	calculateSize();
	
}