Tk button enable/disable?

[Albert Wagner]

I want to enable and disable buttons in Tk.  I tried the following code
but it only partially works:

        # Add a button box to the Open page
        self.openBBx = Pmw.ButtonBox(self.pad1,
            labelpos = 'w',
            frame_borderwidth = 2,
            frame_relief = 'groove',
            orient = 'vertical')
        self.openBBx.pack(side='right', padx=3)

        #add buttons to box
        self.newButton = self.openBBx.add('New',
            command=self.newDBrequest)
        self.openButton = self.openBBx.add('Open',
            command=self.openDBrequest,
            state='disabled')
        self.closeButton = self.openBBx.add('Close',
            command=self.closeDBrequest,
            state='disabled')
        self.deleteButton = self.openBBx.add('Delete',
            command = self.deleteDBrequest,
            state='disabled')

Then later when conditions dictate:

            self.openButton.state = 'normal'
            self.closeButton.state = 'normal'
            self.deleteButton.state = 'normal'
            self.openButton.update()
            self.closeButton.update()
            self.deleteButton.update()

They are initially disabled OK, but I cannot figure out how to later
enable them.  Any help greatly appreciated.
-- 
Small is Beautiful