Image Tk

[srock321]

Hi,
I am trying to develop an application which can pull images from local drives and also from the web (when provided with the URL). I have started developing using Tkinter. The code developed is:

def Get():
    global tem
    global b 
    b= askopenfilename()
def show():
    global pic
    global tem
    s.set(b)
    pic=PhotoImage(file=b)
    ten=can.create_image(250,200,image=pic)

The 'Get()' is called when clicked on a button named 'Browse' and 'show()' is called when clicked on the 'Show' button.
My questions:
1)This code is displaying the images from local drives, however how do I make it compatible with the images on the web?
2)This application only handles .gif files ( I guess as I am using Tkinter) ,how do I make it compatible with other file types?

Thanks in advance