private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        try {
            //Integer.parseInt(str);
            MatrixEntering me = new MatrixEntering(Integer.parseInt(rowsBox.getText()),Integer.parseInt(colsBox.getText()));
            me.setModal(true);
            me.setVisible(true);
            m=me.getM();
            if(m!=null){
                this.dispose();
            }
        }
        catch(Exception e) {
            JOptionPane.showMessageDialog(this, "Musí být zadaná čísla!", "Chyba vstupních dat", JOptionPane.WARNING_MESSAGE);
        }
        
    }