private void subscribeButton_Click(object sender, EventArgs e)
        {
            string message = "";

            sendEmailMobile("Subscription");
            if (emailChecked && mobileChecked)
            {
                if (isValidEmail && isValidMobile)
                {
                    send2Email = new SendViaEmail(email);
                    send2Email.Subscribe(pubForm);
                    send2Mobile = new SendViaMobile(mobile);
                    send2Mobile.Subscribe(pubForm);
                    message = "Subscription successful!!!";
                }
                else
                {
                    message = "Please check your mobile/ email address";
                }
            }
            else if (emailChecked && !mobileChecked)
            {
                if (isValidEmail)
                {
                    message    = "Subscription successful!!!";
                    send2Email = new SendViaEmail(email);
                    send2Email.Subscribe(pubForm);
                }
                else
                {
                    message = "Please check your email address";
                }
            }
            else if (mobileChecked && !emailChecked)
            {
                if (isValidMobile)
                {
                    message     = "Subscription successful!!!";
                    send2Mobile = new SendViaMobile(mobile);
                    send2Mobile.Subscribe(pubForm);
                }
                else
                {
                    message = "Please check your mobile number";
                }
            }
            MessageBox.Show(message);
        }
        //Subscribe for a notification if subscribe button is clicked
        private void subscribeButton_Click(object sender, EventArgs e)
        {
            string message = "";

            manager.PublishMessage();

            //Check if none of the checkboxes are checked
            sendEmailMobile("Subscription");

            //Check if the email already exists
            if (emailChecked)
            {
                if (manager.emailList.Contains(email))
                {
                    MessageBox.Show("The email already exists");
                    emailExist = true;
                }
            }

            //Check if the mobile already exists
            if (mobileChecked)
            {
                if (manager.mobileList.Contains(mobile))
                {
                    MessageBox.Show("The phone number already exists");
                    mobileExist = true;
                }
            }

            //If the email and/or mobile is valid and new, add it to the list by subscribing
            if (!mobileExist && !emailExist)
            {
                if (emailChecked && mobileChecked)
                {
                    if (isValidEmail && isValidMobile)
                    {
                        send2Email = new SendViaEmail(email);
                        send2Email.Subscribe(manager);
                        send2Mobile = new SendViaMobile(mobile);
                        send2Mobile.Subscribe(manager);
                        message = "Subscription successful!!!";
                    }
                    else
                    {
                        message = "Please check your mobile/ email address";
                    }
                }
                else if (emailChecked && !mobileChecked)
                {
                    if (isValidEmail)
                    {
                        message    = "Subscription successful!!!";
                        send2Email = new SendViaEmail(email);
                        send2Email.Subscribe(manager);
                    }
                    else
                    {
                        message = "Please check your email address";
                    }
                }
                else if (mobileChecked && !emailChecked)
                {
                    if (isValidMobile)
                    {
                        message     = "Subscription successful!!!";
                        send2Mobile = new SendViaMobile(mobile);
                        send2Mobile.Subscribe(manager);
                    }
                    else
                    {
                        message = "Please check your mobile number";
                    }
                }
                if (message != "")
                {
                    MessageBox.Show(message);
                }
            }
        }