def button3(self,event):
<EOL>BlockingInput.pop(self)<EOL>if self.inline:<EOL><INDENT>pass<EOL><DEDENT>else:<EOL><INDENT>self.cs.pop_label()<EOL>self.cs.ax.figure.canvas.draw()<EOL><DEDENT>
This will be called if button 3 is clicked.  This will remove
a label if not in inline mode.  Unfortunately, if one is doing
inline labels, then there is currently no way to fix the
broken contour - once humpty-dumpty is broken, he can't be put
back together.  In inline mode, this does nothing.