jq ---- 实现浏览器全屏

// 点击进入全屏 方法、
var fullscreen=function(){
    elem=document.body;
    if(elem.webkitRequestFullScreen){
        elem.webkitRequestFullScreen();   
    }else if(elem.mozRequestFullScreen){
        elem.mozRequestFullScreen();
    }else if(elem.requestFullScreen){
        elem.requestFullscreen();
    }else{
        //浏览器不支持全屏API或已被禁用
    }
}
// 点击退出全屏 方法
var exitFullscreen=function(){
    var elem=document;
    if(elem.webkitCancelFullScreen){
        elem.webkitCancelFullScreen();    
    }else if(elem.mozCancelFullScreen){
        elem.mozCancelFullScreen();
    }else if(elem.cancelFullScreen){
        elem.cancelFullScreen();
    }else if(elem.exitFullscreen){
        elem.exitFullscreen();
    }else{
        //浏览器不支持全屏API或已被禁用
    }
}