Scrollbar needed to get attached to Canvas

[Shah, Navneet]

I am using Pmw Mega widget. I  already  have canvas with buttons in it.
How can I attached scrollbar to the canvas. Any help will be
appreciated.

Shah

My code goes as follows:

class Demo:
    def __int__(self,parent)
        #Create the canvas
        self.sc=Pmw.ScrolledCanvas(parent,
                     borderframe=1,
                     labelpos ='n',
                     usehullsize = 1,
                     hull_width = 400,
                     hull_height = 300,
           )

          self.sc.pack()
          button=Tkinter.Button(self.sc.interior(), text='Hello')
          button.pack(side='left')