Open Street Maps Leaflet Move Marker example 1

<!DOCTYPE html>
<html lang="en">
  <head>
    <title></title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.css" />
    <style>
@media only screen and (min-width: 600px) {
  body {
    margin-right: 200px;
    margin-left: 200px;
    margin-top: 20px;
  }
}
    #map {
      height: 100%;
    }


    html, body {
      height: 100%;
      margin: 0px;
    }
    </style>
  </head>

  <body>
    <div id="map"> </div>
  </body>
  <script type="text/javascript" src="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.js"></script>
  <script>
    var lat = 26.1635173;
    var lng = -81.5583298;
    var zoom = 15;

    var map = L.map('map').setView([lat,lng], zoom);
    L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
      maxZoom: 19,
      attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a>'
    }).addTo(map);

    var marker = L.marker([lat,lng]).addTo(map);
    setInterval(function(){
      lng += 0.0001;
      let newLatLng = L.latLng(lat,lng);
      marker.setLatLng(newLatLng);
    },100);

    setInterval(function(){
      map.panTo([lat, lng]);
    },5000);
  </script>
</html>