dlg3=UserChoice(label="Your are currently at %.2fkeV - Choose the energy for saving the current motors positions"%(motenergy.position/1000.),values=tab_nrj_choice,defval=idx)
dlg3=UserChoice(label="Your are currently at %.2fkeV - Choose the energy for saving the current motors positions"%(motenergy.position),values=tab_nrj_choice,defval=idx)