Jquery和JS实现浏览器全屏

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
    }
}
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
    }
}  

var docElm = document.documentElement;
//W3C
if (docElm.requestFullscreen) {
docElm.requestFullscreen();
}
//FireFox
else if (docElm.mozRequestFullScreen) {
docElm.mozRequestFullScreen();
}
//Chrome等
else if (docElm.webkitRequestFullScreen) {
docElm.webkitRequestFullScreen();
}
//IE11
else if (elem.msRequestFullscreen) {
elem.msRequestFullscreen();
}
if (document.exitFullscreen) {
document.exitFullscreen();
}
else if (document.mozCancelFullScreen) {
document.mozCancelFullScreen();
}
else if (document.webkitCancelFullScreen) {
document.webkitCancelFullScreen();
}
else if (document.msExitFullscreen) {
document.msExitFullscreen();
}