does anybody know the code you need to change animation

Im trying to do where when you move right the sprite changes to sprite 4 and the when you move left it changes to sprite 3 If someone could help me that could be great.

if I knew how I would honestly

update = function()
  direction = 0
  if keyboard.D then
    // movement stuff
    direction = 1
  end
  if keyboard.A then
    //more movement stuff
    direction = 0
  end
  if direction == 1 then
    sprite = "right"
  elsif direction == 0 then
    sprite = "left"
  else 
    sprite = "neutral"
  end
end

that last "neutral" part is optional if you want an idle drawing. And if the left and right sprites are the same, you can just:

update = function()
  direction = 0
  if keyboard.D then
    // movement stuff
    direction = 1
  end
  if keyboard.A then
    //more movement stuff
    direction = 0
  end
  if direction != 0 then
    sprite = "moving"
  end
end

draw = function()
  screen.setDrawScale(direction)
  screen.drawSprite(sprite,x,y,w,h)
  screen.setDrawScale(direction)

this will simply flip the player, so that you don't need 2 sprites for every action

Thanks so much