private void btn_OK_Click(object sender, EventArgs e)
        {
            bool isPassChanged = false;

            switch (CheckData())
            {
            case 0:
                MessageBox.Show("You must fill in all fields!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Information);
                break;

            case 1:
                MessageBox.Show("Invalid Phone Number!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                break;

            case 2:
                MessageBox.Show("Invalid Email or Password!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                break;

            case 3:
                MessageBox.Show("You must insert an image!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Information);
                break;

            case 4:
                string FileName = tb_Username.Text.Replace(" ", String.Empty) + ".Jpeg";
                userVM.UserName = tb_Username.Text.Replace(" ", String.Empty);
                if (tb_Password.Enabled)
                {
                    userVM.UserPassword = tb_Password.Text.Replace(" ", String.Empty);
                    isPassChanged       = true;
                }
                userVM.UserGmail = tb_Email.Text.Replace(" ", String.Empty);
                userVM.UserPhone = tb_Phone.Text.Replace(" ", String.Empty);
                if (rbtn_Male.Checked)
                {
                    userVM.UserGender = true;
                }
                else
                {
                    userVM.UserGender = false;
                }
                if (Change)
                {
                    UpdateIMG(FileName);
                }
                userVM.ListImg.Clear();
                userVM.ListImg.Add(TempAvatar);
                ///properties to check existed
                Dictionary <string, string> properties = new Dictionary <string, string>();
                properties.Add("phone", userVM.UserPhone);
                properties.Add("gmail", userVM.UserGmail);
                if (ID == 0)
                {
                    if (qLUserBLL.Checkexisted(properties))
                    {
                        qLUserBLL.AddUser(userVM);
                        MessageBox.Show("A new user has been successfully created!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        myDel();
                        this.Dispose();
                    }
                    else
                    {
                        MessageBox.Show("Existed Email or Phone!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
                else
                {
                    properties.Add("code", userVM.UserCode);
                    if (qLUserBLL.Checkexisted(properties))
                    {
                        qLUserBLL.UpdateUser(userVM, listDel, isPassChanged);
                        MessageBox.Show("This user has been successfully updated!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        myDel();
                        this.Dispose();
                    }
                    else
                    {
                        MessageBox.Show("Existed Email or Phone!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }

                break;

            default:
                break;
            }
        }