to identify if device is phone,tablet or desktop

Detectdevice

var osEnvar= {
    name : null,
    names: {
            ios: 'iOS',
            android: 'Android',
            webos: 'webOS',
            blackberry: 'BlackBerry',
            rimTablet: 'RIMTablet',
            mac: 'MacOS',
            win: 'Windows',
            linux: 'Linux',
            bada: 'Bada',
            other: 'Other'
        },
    prefixes: {
            ios: 'i(?:Pad|Phone|Pod)(?:.*)CPU(?: iPhone)? OS ',
            android: '(Android |HTC_|Silk/)', // Some HTC devices ship with an OSX userAgent by default,
                                        // so we need to add a direct check for HTC_
            blackberry: 'BlackBerry(?:.*)Version\/',
            rimTablet: 'RIM Tablet OS ',
            webos: '(?:webOS|hpwOS)\/',
            bada: 'Bada\/'
        },
    getosEnv: function () {
       
         var me= this,
             names = me.names,
            prefixes = me.prefixes,
             userAgent = navigator.userAgent, platform = navigator.platform,i, prefix, match, item, is,name, version = '';
        is = this.is = function(name) {
            return this.is[name] === true;
        };
        
         for (i in prefixes) {
           
            if (prefixes.hasOwnProperty(i)) {
                 prefix = prefixes[i];

                match = userAgent.match(new RegExp('(?:'+prefix+')([^\\s;]+)'));
                if (match) {
                    name = names[i];
                   
                    break;
                }
            }
         }
                        if (!name) {
            name = names[(userAgent.toLowerCase().match(/mac|win|linux/) || ['other'])[0]];
           
        }
                this.name = name;
                if (platform) {
            this.setFlag(platform);
        }

        this.setFlag(name);
                for (i in names) {
            if (names.hasOwnProperty(i)) {
                item = names[i];

                if (!is.hasOwnProperty(name)) {
                    this.setFlag(item, (name === item));
                }
            }
        }
     return this; 
    },
    setFlag: function(name, value) {
        if (typeof value == 'undefined') {
            value = true;
        }

        this.is[name] = value;
        this.is[name.toLowerCase()] = value;

        return this;
    },
        getDeviceInfo : function(){
        var osEnv = this.getosEnv(),
         osName = osEnv.name;
        if (!osEnv.is.Android && !osEnv.is.iOS && /Windows|Linux|MacOS/.test(osName)) {
            deviceType = 'Desktop';
        }
        else if (osEnv.is.iPad || osEnv.is.Android3 || (osEnv.is.Android4 && userAgent.search(/mobile/i) == -1) || navigator.userAgent.search(/Tablet/i) != "-1") {
            deviceType = 'Tablet';
        }
        else {
            deviceType = 'Phone';
        }
             osEnv.setFlag(deviceType, true);
    osEnv.deviceType = deviceType;
return this;
        }
    
}
         
    
​

How to use

osEnvar.getDeviceInfo()