判断是否移动端

function detectmob() {  
    if( navigator.userAgent.match(/Android/i)  
    || navigator.userAgent.match(/webOS/i)  
    || navigator.userAgent.match(/iPhone/i)  
    || navigator.userAgent.match(/iPad/i)  
    || navigator.userAgent.match(/iPod/i)  
    || navigator.userAgent.match(/BlackBerry/i)  
    || navigator.userAgent.match(/Windows Phone/i)  
    ){  
        return true;  
    }  
    else {  
        return false;  
    }  
}