private void mNacistActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_mNacistActionPerformed
        JFileChooser nacti = new JFileChooser();
        nacti.setDialogTitle("Načíst jako...");
        int n = nacti.showOpenDialog(nacti);
        try {
            vstup = Source.loadFile(nacti.getSelectedFile().toString());
        } catch (NullPointerException npe) {
            nacti.hide();
            vstup = "0";
        }
        txtVstup.setText(vstup);
    }//GEN-LAST:event_mNacistActionPerformed