How to align image in vertical screen in blackberry java?

Question

i am developing an app in which i need to align image as shown in below.

 |------------------------------|
 |                              |
 |                              |
 |                              |
 |                              |
 |          |---------|         |
 |          |         |         |
 |          |---------|         |                    
 |                              |
 |                              |
 |                              |
 |                              |
 |                              |
 |                              |
 |                              |
 |                              |
 |                              |
 |______________________________|

i tried below code but i am getting image on top of screen when i executed below code what mistake i have done please help me i am new to blackberry

public final class MyScreen extends MainScreen
{
private BitmapField bitmapField;

/**
 * Creates a new MyScreen object
 */
public MyScreen()
{        
    // Set the displayed title of the screen       
    setTitle("MyTitle");
    VerticalFieldManager MainLayout = new 
    VerticalFieldManager(Manager.USE_ALL_HEIGHT|Manager.USE_ALL_WIDTH|
  Manager.VERTICAL_SCROLLBAR);
  HorizontalFieldManager hfm =  new      
  HorizontalFieldManager(Field.FIELD_HCENTER | Field.FIELD_VCENTER);
    Bitmap logo1 = Bitmap.getBitmapResource("Lock.png");
    bitmapField = new BitmapField(logo1);
    hfm.add (bitmapField);
    MainLayout.add(hfm);
    add(MainLayout);
}
}