Change Main Screen Background in Blackberry

In here i tried several methods to do that. All methods give me some out put but not perfect. most of examples gives the out put but also gives ugly scoll bar. I used folloeing coding to set main screen backgroung color with out the scoll bar in component pack 4.5.

public class frmLogin extends MainScreen {

VerticalFieldManager vmain;

public frmLogin() 

{

       super(NO_VERTICAL_SCROLL);

      vmain = new VerticalFieldManager(USE_ALL_HEIGHT |USE_ALL_WIDTH)

     {

 protected void paint(net.rim.device.api.ui.Graphics graphics) 

        {

     graphics.setBackgroundColor(0xe6e7e8);  // 0xRRGGBB or Color.Blue

         graphics.clear();

 super.paint(graphics);

        } 

     };

     

     // Add other controlers to vmain

     

     add(vmain);

}