如果地理定位成功(成功),如何调整函数内的缩放级别?
function createMap(lat, lng) {
var mapOptions = { center: new google.maps.LatLng(lat, lng), 
  zoom: 12,
  scrollwheel: false,
  mapTypeId: google.maps.MapTypeId.ROADMAP };
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
function initialize() {
if(navigator.geolocation) {
  success = function(position) {
    createMap(position.coords.latitude, position.coords.longitude);
  };
  error = function() { createMap(99.648493, -99.410812); }
  navigator.geolocation.getCurrentPosition(success, error);
 }
}