AlertDialog.Builder builder_serial = new AlertDialog.Builder(this);
builder_serial.setTitle("Select a tracker");
builder_serial.setItems(trackers,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
AlertDialog.Builder builder_serial = new AlertDialog.Builder(this);
builder_serial.setTitle("Select a tracker");
builder_serial.setItems(trackers,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {