Judge different devices to display different pages

var browser = {
    
      
    versions:function(){
    
       
        var u = navigator.userAgent, app = navigator.appVersion;   
        return {
    
    //移动终端浏览器版本信息   
           trident: u.indexOf('Trident') > -1, //IE内核  
           presto: u.indexOf('Presto') > -1, //opera内核  
           webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核  
           gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核  
           mobile: !!u.match(/AppleWebKit.*Mobile.*/), //是否为移动终端  
           ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios终端  
           android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android终端或者uc浏览器  
           iPhone: u.indexOf('iPhone') > -1 , //是否为iPhone或者QQHD浏览器  
           iPad: u.indexOf('iPad') > -1, //是否iPad    
           webApp: u.indexOf('Safari') == -1, //是否web应该程序，没有头部与底部
           MiPad: u.indexOf('MI PAD') > -1//是否Mi Pad
        };
  }(),  
  language:(navigator.browserLanguage || navigator.language).toLowerCase()  
};
//当前是手机端 但未显示手机页面
if((browser.versions.mobile || browser.versions.android || browser.versions.iPhone)){
    
    
	var lastIndex=location.href.lastIndexOf("/")+1;
	var sPageName=location.href.substring(lastIndex);
	if(sPageName.indexOf("pc.html")>-1){
    
    
	    location.href=location.href.replace('pc.html','mobile.html');
	}
	//var _ad = document.getElementsByClassName('doubleTwelve')[0];
	//_ad.setAttribute("src","http://images.wish3d.com/tuxingis/assets/img/course/frenchpage/750_350.JPG");
}  

//当前不是手机端 但显示手机页面
if(!(browser.versions.mobile||browser.versions.android|| browser.versions.iPhone)){
    
    
	var lastIndex=location.href.lastIndexOf("/")+1;
	var sPageName=location.href.substring(lastIndex);
	if(sPageName.indexOf("mobile.html")>-1){
    
    
	    location.href=location.href.replace('mobile.html','pc.html');
	}
}

//设置视口
var metaEl = document.querySelector('meta[name="viewport"]');
if (!metaEl) {
    
    
	metaEl = document.createElement('meta');
	metaEl.setAttribute('name', 'viewport');
	document.head.appendChild(metaEl);
}
metaEl.setAttribute('content', 'width=device-width,user-scalable=no,initial-scale=1,minimum-scale=1,maximum-scale=1');
document.documentElement.style.fontSize = '16px';