XEP-0333, implementation using javascript

I am working on a chat in a website using openfire and strophe js. I want to integrate message seen function like whatsapp. But I am not getting how to implement xep-0333 with strophe js. Please help with this.

Thanks

Here is an example of ready methods on how to use XEP-0333, especially for delivered & read statuses:

Strophe.addNamespace('CHAT_MARKERS', "urn:xmpp:chat-markers:0");

...

sendDeliveredMarker: function(to, from, originalMessageId) {
    var stanzaParams = {
        type: 'chat',
        from: from,
        id: "<id>",
        to: to
    };

    var messageStanza = $msg(stanzaParams);
    messageStanza
        .c('received', {
            xmlns: "urn:xmpp:chat-markers:0",
            id: originalMessageId
        })
        .up();

    this.xmppClient.send(messageStanza);
},

sendReadMarker: function(to, from, originalMessageId) {
    var stanzaParams = {
        type: 'chat',
        from: from,
        id: "<id>",
        to: to
    };

    var messageStanza = $msg(stanzaParams);
    messageStanza
        .c('displayed', {
            xmlns: "urn:xmpp:chat-markers:0",
            id: originalMessageId
        })
        .up();

    this.xmppClient.send(messageStanza);
},