[JS代码]如何判断ipad或者iphone是否为横屏或者竖屏 - portrait或者landscape

      //判断横屏或者竖屏

        function orient() {

            //alert('gete');

            if (window.orientation == 0 || window.orientation == 180) {

                document.getElementById("os").innerHTML += "portrait";

                //$("body").attr("class", "portrait");

                orientation = 'portrait';

                return false;

            }

            else if (window.orientation == 90 || window.orientation == -90) {

                document.getElementById("os").innerHTML += "landscape";

               // $("body").attr("class", "landscape");

                orientation = 'landscape';



                return false;

            }

        }

window.onresize = function (){orient();}