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>