what is the key code for shift+tab?

Question

I am working on key mapping. The problem is that when I press the TAB button down it navigates to the next input field.

TAB has key of 9 and
DO

Answer 1

in my GWT case

if(event.isShiftKeyDown() && event.getNativeKeyCode() == KeyCodes.KEY_TAB){
    //Do Something
}