function ber_gra02()
 {
  var x,max,min;


  switch (level)
  {
   case 1 :
   {
    a=zufall01('2','9');
    b=zufall01('2','9');
    break;
   }
   case 2 :
   {
    if (operator == ':' || operator == '*')
     {
      a=zufall01('10','20');
      b=zufall01('2','9');
     }
    else
     {
      a=zufall01('10','99');
      b=zufall01('2','9');
     }

    break;
   }
   case 3 :
   {
    if (operator == ':' || operator == '*')
     {
      a=zufall01('10','20');
      b=zufall01('10','20');
     }
    else
     {
      a=zufall01('10','99');
      b=zufall01('10','99');
     }

    break;
   }
   case 4 :
   {
    if (operator == ':' || operator == '*')
     {
      a=zufall01('20','30');
      b=zufall01('10','20');
     }
    else
     {
      a=zufall01('100','999');
      b=zufall01('10','99');
     }

    break;
   }
   case 5 :
   {
    if (operator == ':' || operator == '*')
     {
      a=zufall01('20','30');
      b=zufall01('20','30');
     }
    else
     {
      a=zufall01('100','999');
      b=zufall01('100','999');
     }
    break;
   }
   default:
   {
    window.document.forms[0].elements[9].value = ("Kein Level vorgegeben");
   }

  }


  switch (operator)
  {
   case '+' :
   {
    ergebnis = a+b;
    aufgabentyp = "Addition";
    if (level == 1)
       Maxtime = 30;
    else if(level == 2)
       Maxtime = 60;
    else if(level == 3)
       Maxtime = 90;
    else if(level == 4)
       Maxtime = 120;
    else if(level == 5)
       Maxtime = 150;
       //window.document.forms[0].elements[14].value =Maxtime;
    break;
   }
   case '-' :
   {
    max = Math.max(a , b);
    min = Math.min(a , b);
    a = max;
    b = min;
    ergebnis = a-b;
    aufgabentyp = "Subtraktion";
    if (level == 1)
       Maxtime = 30;
    else if(level == 2)
       Maxtime = 60;
    else if(level == 3)
       Maxtime = 90;
    else if(level == 4)
       Maxtime = 120;
    else if(level == 5)
       Maxtime = 150;
    break;
   }
   case '*' :
   {
    ergebnis = a*b;
    aufgabentyp = "Multiplikation";
    if (level == 1)
       Maxtime = 30;
    else if(level == 2)
       Maxtime = 60;
    else if(level == 3)
       Maxtime = 120;
    else if(level == 4)
       Maxtime = 240;
    else if(level == 5)
       Maxtime = 480;
    break;
   }
   case ':' :
   {
    x = a*b;
    a = x;
    ergebnis = a/b;
    aufgabentyp = "Division";
    if (level == 1)
       Maxtime = 30;
    else if(level == 2)
       Maxtime = 60;
    else if(level == 3)
       Maxtime = 120;
    else if(level == 4)
       Maxtime = 240;
    else if(level == 5)
       Maxtime = 480;
    break;
   }
   default:
   {
    window.document.forms[0].elements[9].value = ("Operator nicht gefunden");
   }

  }

  return ergebnis;
 }