前一段时间HTML5也算是定稿了，CSDN之类的网站也对全屏API进行了部分介绍。但是查了中文资料就没有全屏检测的。下面给出完整的全屏以及检测的方式

    function isFullSrc(){
        if((window.fullScreen) ||(window.innerWidth == screen.width && window.innerHeight == screen.height)) 
            return true;
        else 
            return false;
    }

    function requestFullScreen() {
        var de = document.documentElement;
        if (de.requestFullscreen) {
            de.requestFullscreen();
        } else if (de.mozRequestFullScreen) {
            de.mozRequestFullScreen();
        } else if (de.webkitRequestFullScreen) {
            de.webkitRequestFullScreen();
        }
    }

    function exitFullscreen() {
        var de = document;
        if (de.exitFullscreen) {
            de.exitFullscreen();
        } else if (de.mozCancelFullScreen) {
            de.mozCancelFullScreen();
        } else if (de.webkitCancelFullScreen) {
            de.webkitCancelFullScreen();
        }
    }