func addBoundry()
    {
        var points=[CLLocationCoordinate2DMake(39.02, -76.9),CLLocationCoordinate2DMake(38.97, -76.9),CLLocationCoordinate2DMake(38.97, -77),CLLocationCoordinate2DMake(39.02, -77)]

        let polygon = MKPolygon(coordinates: &points, count: points.count)

        mapView.addOverlay(polygon)
    }

    let regionRadius: CLLocationDistance = 1000
    func centerMapOnLocation(location: CLLocation) {
        let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
                                                                  regionRadius * 2.0, regionRadius * 2.0)
        mapView.setRegion(coordinateRegion, animated: true)
    }
    func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
        if overlay is MKPolygon {
            let polygonView = MKPolygonRenderer(overlay: overlay)
            //polygonView.strokeColor = UIColor.magentaColor()
            polygonView.strokeColor = UIColor(red: 0/255.0, green: 180/255.0, blue: 0/255.0, alpha: 0.4)

            return polygonView
        }

        return nil
    }