public void kresli(Graphics g) {

        Grafic a = new Grafic();
        a.drawSource(vstup, poziceScrolu, Displej, DisplejScrollBar, g);
        a.drawResult(vysledek, poziceScrolu, Displej, DisplejScrollBar, g);
        txtVstup.addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
            }

            @Override
            public void keyPressed(KeyEvent e) {
            }

            @Override
            public void keyReleased(KeyEvent e) {
            }
        });

        try {
            MathList<Variable> var = f.VariableList();
            v = (new MathList()).fillColection(vstup).fromMathList();
            for (int i = 0; i < var.size(); i++) {
                v.changeVariable(var.get(i));
            }
            var.clear();
            var.addAll(v.variablesInList().reductionDuplicates());
            f.setTable(var);
        } catch (IndexOutOfBoundsException ex) {
        } catch (VstupException ex) {
            Logger.getLogger(Calc.class.getName()).log(Level.SEVERE, null, ex);
        }
        f.repaint();
        btnOdmocnina.setVisible(false);
        //btnMocnina.setVisible(false);
    }