private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
        int a[][] = new int[n][n];
        String tmp = new String();
           for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {

                String x = JOptionPane.showInputDialog("Zadaj prvok matice A[" + i + "," + j + "]");
                a[i][j] = Integer.parseInt(x);
                tmp += x + "/n";
                //jTextArea1.add(x + "/n");
            }
        }
        jTextArea1.setText(tmp);
    }