Deleting and changing a tkinter event binding

How do i stop an event from being processed or switch what function is called for it?

Revised Code:

from Tkinter import *

class GUI:
    def __init__(self,root):
        Window = Frame(root)
        self.DrawArea = Canvas(Window)
        self.DrawArea.pack()
        Window.pack()

        self.DrawArea.bind("<Button 1>",self.starttracking)

    def updatetracking(self,event):
        print event.x,event.y

    def finishtracking(self,event):
        self.DrawArea.bind("<Button 1>",self.starttracking)
        self.DrawArea.unbind("<Motion>")

    def starttracking(self,event):
        print event.x,event.y
        self.DrawArea.bind("<Motion>",self.updatetracking)
        self.DrawArea.bind("<Button 1>",self.finishtracking)



if __name__ == '__main__':
    root = Tk()
    App = GUI(root)
    root.mainloop()