Can this Tkinter script be simplified?

[Greg Wilson]

Hello.  The enclosed script does what I want it to do, but looks overly
complex
to me --- I'd be grateful if someone could tell me whether/how it could be
simplified.  In particular, can the IntVar() be initialized when it's
created, and
can actions be bound to state changes in active variables?
Thanks,
Greg

------------8<-----------------

Question = """
Create a GUI that displays the number of times a button has been
clicked, with a checkbox that controls whether the button can be
clicked.
"""

from Tkinter import *

class Counter(Frame):

    def __init__(self, parent=None):
        Frame.__init__(self); self.pack()
        self.counter = 0

        self.chkVar = IntVar()
        self.chkVar.set(1)
        self.check = Checkbutton(self, text="enable",
                                 variable=self.chkVar,
                                 command=self.setState)
        self.check.pack(side=LEFT)

        self.button = \
            Button(self, text="click",
                   command=self.incr, state=NORMAL)
        self.button.pack(side=LEFT)

        self.caption = Label(self, text=('%d' % self.counter))
        self.caption.pack(side=LEFT)

    def setState(self):
        if self.chkVar.get():
            self.button.configure(state=NORMAL)
        else:
            self.button.configure(state=DISABLED)

    def incr(self):
        self.counter = self.counter + 1
        self.caption.config(text=('%d' % self.counter))

root = Tk()
roller = Counter(root)
root.mainloop()