def Load_Simulation(self,event=None):

        self.canvas.Show(False)
        if self.modified:
            (root,sfname)=os.path.split(self.params['save_sim_file'])
            dlg=MessageDialog(self, 
                          text="Do you want to save the changes you made to %s?" % sfname,
                          title="Load Simulation", ok=0, yes_no=1,cancel=1)
            result=dlg.ShowModal()
            dlg.Destroy()