<script>
  function kamil(a, b)
  {
    document.write(a+" + "+b+" = "+(a+b)+"<br>");
  }
  //************************************************
  function kamil2(a, b)
  {
    return (a+" + "+b+" = "+(a+b)+"<br>");
  }
  //************************************************
  function mnozenie(a, b)
  {
    return (a*b);
  }
  kamil(1,2);
  document.write(kamil2(3,4));
  document.write(mnozenie(2,4));
</script>