JS 判断浏览器客户端类型(ipad,iphone,android)

如何判断是否是 iPad 浏览器呢，关键是看它的 User Agent 中是否有 iPad。iPad 使用的是 Safari Mobile 浏览器，他的的 User Agent 是：

Mozilla/5.0 (iPad; U; CPU OS 3_2 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Version/4.0.4 Mobile/7B334b Safari/531.21.10

Javascript代码
function is_iPad(){ 
    var ua = navigator.userAgent.toLowerCase(); 
    if(ua.match(/iPad/i)=="ipad") { 
       return true; 
    } else { 
       return false; 
    } 
}
因此，判断ipad,iphone,android的代码为：
<script type="text/javascript"> 
var bForcepc = fGetQuery("dv") == "pc"; 
function fBrowserRedirect(){ 
    var sUserAgent = navigator.userAgent.toLowerCase(); 
    var bIsIpad = sUserAgent.match(/ipad/i) == "ipad";   
    var bIsIphoneOs = sUserAgent.match(/iphone os/i) == "iphone os"; 
    var bIsMidp = sUserAgent.match(/midp/i) == "midp"; 
    var bIsUc7 = sUserAgent.match(/rv:1.2.3.4/i) == "rv:1.2.3.4"; 
    var bIsUc = sUserAgent.match(/ucweb/i) == "ucweb"; 
    var bIsAndroid = sUserAgent.match(/android/i) == "android"; 
    var bIsCE = sUserAgent.match(/windows ce/i) == "windows ce"; 
    var bIsWM = sUserAgent.match(/windows mobile/i) == "windows mobile"; 
    if(bIsIpad){ 
        var sUrl = location.href;     
        if(!bForcepc){ 
            window.location.href = "http://ipad.mail.163.com/"; 
        } 
    } 
    if(bIsIphoneOs || bIsAndroid){ 
        var sUrl = location.href;     
        if(!bForcepc){ 
            window.location.href = "http://smart.mail.163.com/"; 
        } 
    } 
    if(bIsMidp||bIsUc7||bIsUc||bIsCE||bIsWM){ 
        var sUrl = location.href;     
        if(!bForcepc){ 
            window.location.href = "http://m.mail.163.com/"; 
        } 
    } 
} 
function fGetQuery(name){//获取参数值 
    var sUrl = window.location.search.substr(1); 
    var r = sUrl.match(new RegExp("(^|&)" + name + "=([^&]*)(&|$)")); 
    return (r == null ? null : unescape(r[2])); 
} 
function fShowVerBlock(){    
    if(bForcepc){ 
        document.getElementById("dv_block").style.display = "block"; 
    } 
    else{ 
        document.getElementById("ad_block").style.display = "block"; 
    } 
} 
fBrowserRedirect(); 
</script>