How can I prevent repeated values from previous onChildAdded calls in Firebase Realtime Database with JavaScript and jQuery event handling?

Question

i am trying to do realtime message with firebase using javascript but i have problem with onChildAdded because everytime i click button to change user onChildAdded returns previous repeated values. Is there a way to get onChildAdded to be called again but not return previous values?

function selectAdmin(reciveName) {
    onChildAdded(newMsg, (data) => {
        
        if ((data.val().senderName === reciveName) && (data.val().reciveName === currentUser)) {
            console.log(data.val());
            messagesContainer.append([
                `<li class="other"><span><img src="${data.val().senderAvatar}" alt=""></span>`,
                data.val().message,
                `</li>`
            ].join(''));
        } else if (data.val().senderName === currentUser && data.val().reciveName === reciveName) {
            var currentName = data.val().senderName;
            messagesContainer.append([
                `<li class="self"><span><img src="${data.val().senderAvatar}" alt=""></span>`,
                data.val().message,
                `</li>`
            ].join(''));
        }
    });
}




$('ul').on('click', '.chat_with_user', function() {
    var id = $(this).attr('id');
    reciveName = id;
    messagesContainer.html('');
    selectAdmin(reciveName);
    messagesContainer.finish().animate({
        scrollTop: messagesContainer.prop("scrollHeight")
    }, 250);
});