private void OduzimanjeMatricaButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_OduzimanjeMatricaButtonActionPerformed
        int number1, number2, number3, number4, number5, number6, number7, number8;
        try {
            number1 = Integer.parseInt(
                    this.a11numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number a11", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number2 = Integer.parseInt(
                    this.a12numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number a12", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }

        try {
            number3 = Integer.parseInt(
                    this.a21numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number a21", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number4 = Integer.parseInt(
                    this.a22numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number a22", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number5 = Integer.parseInt(
                    this.b11numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number b11", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number6 = Integer.parseInt(
                    this.b12numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number b12", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number7 = Integer.parseInt(
                    this.b21numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number b21", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        try {
            number8 = Integer.parseInt(
                    this.b22numberText.getText());
        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(this, "Wrong number b22", "ERROR", JOptionPane.ERROR_MESSAGE);
            return;
        }
        int Rezultat = number1 - number5;
        this.ResenjeLabel1.setText(
                " " + Rezultat);

        int Rezultat1 = number2 - number6;
        this.ResenjeLabel2.setText(
                " " + Rezultat1);

        int Rezultat2 = number3 - number7;
        this.ResenjeLabel3.setText(
                " " + Rezultat2);

        int Rezultat3 = number4 - number8;
        this.ResenjeLabel4.setText(
                " " + Rezultat3);

    }//GEN-LAST:event_OduzimanjeMatricaButtonActionPerformed