title: No reaction back or end
body: <p>I have a question in my program, which asks if a user want to go back to menu or they want to end the program.</p>
  
  <p>First I had this code in the <code>back()</code> function, but then I moved it to code (out of <code>def</code>), because I thought there is something wrong with <code>def</code>. But it is still not working. The part of code I mean is selected between <code>#</code>.</p>
  
  <pre><code>while True:
      zoznam()
  
  zam=input("\n   Nacitaj hodnotu zamestnanca: ")
  time.sleep(.5)
  clear()
  
  if zam == "1":
      print("Zamestnanec: Ewo Salae")
      print("K výplate {} EUR.".format(PD))
      print("\n")
      desto = PD % 200
      desto2 = int((PD - desto)/200)
      print("200 EUR - {}".format(desto2))
      vyplata()
  #
      bb = str(input("Vratit sa do zoznamu - Z\n Ukončiť program - U\n Vasa moznost: "))
      if bb == "U" or "u"():
          print("stop")
      if bb == "z" or "Z"():
          print("Návrat do menu")
  #
  </code></pre>
  
  <p>The <code>def</code> looks:</p>
  
  <pre><code>def back():
      bb = str(input("Vratit sa do zoznamu - Z\n Ukončiť program - U\n Vasa moznost: "))
      if bb == "U" or "u":
          print("stop")
      if bb == "z" or "Z":
          print("Návrat do menu")
  </code></pre>