I'm trying to use WASD as movement keys instead of the arrow keys. My code is below. Arrow keys are working perfectly but i"m not getting any response from WASD. Any suggestions?

def update
    if button_down? Gosu::KbLeft or button_down? Gosu::KbA then
      @player.turn_left
    end
    if button_down? Gosu::KbRight or button_down? Gosu::KbD then
      @player.turn_right
    end
    if button_down? Gosu::KbUp or button_down? Gosu::KbW then
      @player.accelerate
    end
    @player.move
  end