def smallInMiddle():
  file = pickAFile()
  src = makePicture(file)
  target = makeEmptyPicture(640,480)
  smallWidth=getWidth(src)
  smallHeight=getHeight(src)
  startx=(getWidth(target)/2)-(smallWidth/2)
  starty=(getHeight(target)/2)-(smallHeight/2)
  print startx
  print starty
  
  x=startx
  i=1
  while i<smallWidth:
    j=1
    y=starty
    while j<smallHeight:
      sourcePixel=getPixel(src,i,j)
      targetPixel=getPixel(target,x,y)
      color=getColor(sourcePixel)
      setColor(targetPixel,color)
      y=y+1
      j=j+1
    i=i+1
    x=x+1
  show(target)