How to alert message before Response.redirect? or other way

Question

I have a button on my update page. This button redirects and refreshes the page after sending sms

 

I want that;

 

If the user pushes the button and sends sms 1 time, do not press the same button 2 times unless the page is closed.

 

In fact, I installed the structure, but because the button response is redirect, my page refreshes every time and never falls into the following else. How can I solve this?

 

Response redirect(in controller)

public void SMSGonder(int flowId)
    {
        flow flow = db.flow.Find(flowId);
        string meetingDate = "";
        foreach (var item in db.sp_get_meeting(flowId))
        {
            meetingDate = item.meetingDate.ToString("dd.MM.yyyy HH:mm");
        }
        DakikSMSMesajGonder2(flow.flowPhone.ToString(), flow.flowName, meetingDate, null);
        Response.Redirect("~/flows/Edit?id=" + flowId);
    }

href button;

<div class="col-md-4">
<a class="btn btn-default" id="sms" href="/flows/[email protected]">Sent SMS</a>
</div>

and JQuery;

$("#sms").click(function () {
            var $foo = $(this);
            if(!$foo.data('clicked'))
            {
                alert("SMS sent successfully!");
            }
            else {
                alert("You've already sent this sms.");
            }
            $foo.data('clicked', true);
        });