function calc_sidebar_width()
	{
	var w = screen.width;
	var side = (w-848)/2;
	side = side-71;
	var style = 'style="width:'+side+'px;"';
	var dA = document.getElementById('sideA');
	dA.style.width=side+"px";
	var dB = document.getElementById('sideB');
	dB.style.width=side+"px";
	}