if (navigator.userAgent.match(/iPhone/i) || navigator.userAgent.match(/iPad/i)) {
  				var viewportmeta = document.querySelector('meta[name="viewport"]');
  				if (viewportmeta) {
    				viewportmeta.content = 'width=device-width, minimum-scale=1.0, maximum-scale=1.0';
    				document.body.addEventListener('gesturestart', function() {
      				viewportmeta.content = 'width=device-width, minimum-scale=0.25, maximum-scale=1.6';
    				}, false);
  				}
			}