List<Overlay> mapOverlays = mapView.getOverlays();
     Drawable drawable = this.getResources().getDrawable(resID);
     HelloItemizedOverlay itemizedoverlay = new        HelloItemizedOverlay(drawable,this);
     GeoPoint point = new GeoPoint((int)latd,(int)lond);
     OverlayItem overlayitem = new OverlayItem(point, name, name);
     itemizedoverlay.addOverlay(overlayitem);
     mapOverlays.add(itemizedoverlay);

List<Overlay> mapOverlays = mapView.getOverlays();
     mapOverlays.clear() // add this to remove previous
     Drawable drawable = this.getResources().getDrawable(resID);
     HelloItemizedOverlay itemizedoverlay = new        HelloItemizedOverlay(drawable,this);
     GeoPoint point = new GeoPoint((int)latd,(int)lond);
     OverlayItem overlayitem = new OverlayItem(point, name, name);
     itemizedoverlay.addOverlay(overlayitem);
     mapOverlays.add(itemizedoverlay);