點擊按鈕控制video標籤的全屏效果

$('.videofull').click(function(){
	var videobox = $(this).siblings('.videobox');
	var videoObj = videobox.find('video')[0];
	if(videoObj.requestFullScreen) {
		videoObj.requestFullScreen(); 
	} else if(videoObj.mozRequestFullScreen) {
		videoObj.mozRequestFullScreen(); 
	} else if(videoObj.webkitRequestFullScreen) {
		videoObj.webkitRequestFullScreen(); 
	}
})