js判断web网站是手机端访问的还是PC端访问的

checkLoginStatus = function () {
var system = {
win: false,
mac: false,
xll: false,
ipad:false
};
//检测平台
var p = navigator.platform;
system.win = p.indexOf("Win") == 0;
system.mac = p.indexOf("Mac") == 0;
system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
system.ipad = (navigator.userAgent.match(/iPad/i) != null)?true:false;
if (system.win || system.mac || system.xll||system.ipad) {
return false;
} else {
return true;
}

};