private void button_change_Click(object sender, EventArgs e)
        {
            ArrayList userInfo = new ArrayList();


            String givenOldPass  = textBox_oldpw.Text;
            String givenNewPass  = textBox_newpw.Text;
            String givenConfPass = textBox_confirm.Text;


            if (String.IsNullOrEmpty(textBox_oldpw.Text) || String.IsNullOrEmpty(textBox_newpw.Text) ||
                String.IsNullOrEmpty(textBox_confirm.Text))
            {
                MessageBox.Show("Fill up all data");
            }

            else
            {
                DatabaseHelperClass ob1 = new DatabaseHelperClass();


                if (ob1.checkPassword(givenOldPass, givenID))
                {
                    if (String.Compare(givenNewPass, givenConfPass) == 0)
                    {
                        userInfo.Add(textBox_newpw.Text);


                        DatabaseHelperClass ob = new DatabaseHelperClass(userInfo);
                        if (ob.changePassword(givenID))
                        {
                            MessageBox.Show("Password Changed");
                        }
                        else
                        {
                            MessageBox.Show("Error Changing Password");
                        }
                    }
                    else
                    {
                        MessageBox.Show("Password Doesn't Match");
                    }
                }
                else
                {
                    MessageBox.Show("Wrong old password !");
                }
            }
        }