function popVR(pano) {
if (document.all)
var xMax = screen.width, yMax = screen.height;
else
if (document.layers)
var xMax = window.outerWidth, yMax = window.outerHeight;
else
var xMax = 800, yMax = 600;
var xOffset = (xMax - 420)/2, yOffset = (yMax - 270)/2;
window.open(pano+'.html','PanoVR','width=420,height=270,screenX='+xOffset+',screenY='+yOffset+',top='+yOffset+',left='+xOffset+'');
}