function initialize() {
  var latlng = new google.maps.LatLng(51.829, -4.872);
  var myOptions = {
    zoom: 9,
    center: latlng,
    mapTypeId: google.maps.MapTypeId.HYBRID
  };
  var map = new google.maps.Map(document.getElementById("googlemap"), myOptions);
  
  display_markers(map);
}