In LWUIT, a white rectangular background appears when the button is pressed, how to remove it?

Using LWUIT, I have a Form (form1) which contains a Button (see the silver arrow at the bottom of the Form in the left image below). This Button is constructed using an image which has a transparent background to give the effect of a non-rectangular Button. When the Button is pressed it shows another Form (form2).

But unfortunately, when the user presses this Button, a white rectangular background appears for a few milliseconds in the background of the image. see the right image below:

The question is:
How may I prevent this white rectangle from being appeared after pressing the Button ?

You have modified the state of the button when it is selected or unselected. You also have to modify pressed style. You can do it with button.getPressedStyle()

Try:

button.getPressedStyle().setBorder(null);
button.getPressedStyle().setBgTransparency(0);