var viewportwidth;
 var viewportheight;
 if (typeof window.innerWidth != 'undefined')
 {
      viewportwidth = window.innerWidth,
      viewportheight = window.innerHeight
 }
 else if (typeof document.documentElement != 'undefined'
     && typeof document.documentElement.clientWidth !=
     'undefined' && document.documentElement.clientWidth != 0)
 {
       viewportwidth = document.documentElement.clientWidth,
       viewportheight = document.documentElement.clientHeight
 }
 else
 {
       viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
       viewportheight = document.getElementsByTagName('body')[0].clientHeight
 }

var leftEdge;
	leftEdge = viewportwidth - 900; 
	leftEdge = leftEdge/2;
	if (leftEdge <= 0) { leftEdge = 0; }
	var menuDisplay = document.getElementById('popout1');
	menuDisplay.style.left = leftEdge-20;
	var menuDisplay = document.getElementById('popout2');
	menuDisplay.style.left = leftEdge+207;