html5重力感应

	var orientationTimmer = null;
	window.addEventListener(window[‘onorientationchange‘] ? ‘orientationchange‘ : ‘resize‘, function(){
       clearTimeout(orientationTimmer);

       orientationTimmer = setTimeout(function(){
       		if(window.orientation){
       			switch(window.orientation){
	       			case 90:
	       				alert(‘左旋‘)
	       				break;
	       			case -90:
	       				alert(‘右旋‘)
	       				break;
	       		}
       		}
       },200);
       
    }, false);