Edit in JSFiddle

var map;

function initMap(center) {
  map = $("#map").geomap({
    center: center || [-71.0597732, 42.3584308],
    zoom: 14
  });
}

if (navigator.geolocation) {
  navigator.geolocation.getCurrentPosition(function (p) {
    initMap([p.coords.longitude, p.coords.latitude]);
  }, function (error) {
    initMap();
  });
} else {
  initMap();
}

<div id="map"></div>