Tkinter Images

[Tuvas]

I've been trying to use a canvas to display different pictures on a
Tkinter interface. However, it doesn't seem to update the information.
Ei, I have something like this.

canvas=Canvas(master,blah...)
canvas.pack()

def change_pic(path):
  global pic
  image=Image()               #I'm using PIL to use the images, but I
don't think it's depended... This code's not the important one...
  canvas.create_image(1,1,image=image, anchor=NW)

change_pic("test1.jpg")

I have written a simple scipt that just displays an image, without any
problems. However, when I try to change the image dynamically, it
doesn't work. If needed I can put the real code, however, it's a bit
complicated to do so, this computer doesn't support copying from the
terminal to the web browser. Thanks for the help!