called on load button

def on_load(self, event):
        '''called on load button'''
        dlg = wx.FileDialog(None, self.settings.get_title(), '', "", '*.*', wx.FD_OPEN)
        if dlg.ShowModal() == wx.ID_OK:
            self.settings.load(dlg.GetPath())
        # update the controls with new values
        for label in self.setting_map.keys():
            setting = self.setting_map[label]
            ctrl = self.controls[label]
            value = ctrl.GetValue()
            if isinstance(value, str) or isinstance(value, unicode):
                ctrl.SetValue(str(setting.value))
            else:
                ctrl.SetValue(setting.value)