Django admin Google maps Location picker (api v3)

jquery.location_picker.js

google.load("maps", "3");

$(document).unload(function(){
    GUnload();
});

$(document).ready(function(){
    $("input.location_picker").each(function (i) {
        var map = document.createElement('div');
        map.className = "location_picker_map";
        this.parentNode.insertBefore(map, this);
        $(this).css('display','none');
        
        var lat = 11.241944;
        var lng = -74.205278;
        var self = this;

        if (this.value.split(',').length === 2) {
            var values = this.value.split(',');
            lat = values[0];
            lng = values[1];
        }

        var latitude = parseFloat(lat);
        var longitude = parseFloat(lng);
        var center = new google.maps.LatLng(latitude, longitude)
        this.value = String(latitude) + "," + String(longitude);

        var mapOptions = {
          center: { lat: latitude, lng: longitude},
          zoom: 13 
        };

        var map = new google.maps.Map(map, mapOptions);

        var marker = new google.maps.Marker({ 
            position: center,
            map : map
        });

        google.maps.event.addListener(map, 'click', function(event) {
            self.value = event.latLng.lat() + "," + event.latLng.lng();
            if (marker === null || marker === undefined) {
              marker = new google.maps.Marker({ 
                position: event.latLng,
                map : map
              });
            } else {
              marker.setPosition(event.latLng);
            }
        });

    });
});

location_picker.css

.location_picker_map {
  width: 400px;
  height: 300px;
  border: 1px solid black;
  padding: 2px;
  display: inline-block;
}

models.py

from django.db import models
from YOUR_APP.widgets import *

class Place(models.Model):
    """(Place description)"""    
    location = LocationField(blank=True, max_length=255)

widgets.py

from django import forms
from django.db import models
from django.conf import settings

class LocationPickerWidget(forms.TextInput):
    class Media:
        css = {
            'all': (
                settings.STATIC_URL + 'css/location_picker.css',
            )
        }
        js = (
            'http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js',
            'http://www.google.com/jsapi?key=' + settings.MAPS_API_KEY,
            settings.STATIC_URL + 'js/jquery.location_picker.js',
        )

    def __init__(self, language=None, attrs=None):
        self.language = language or settings.LANGUAGE_CODE[:2]
        super(LocationPickerWidget, self).__init__(attrs=attrs)

    def render(self, name, value, attrs=None):
        if None == attrs:
            attrs = {}
        attrs['class'] = 'location_picker'
        return super(LocationPickerWidget, self).render(name, value, attrs)

class LocationField(models.CharField):

    def formfield(self, **kwargs):
        kwargs['widget'] = LocationPickerWidget
        return super(LocationField, self).formfield(**kwargs)