ASP.Net MVC 5 Form in a Twitter Bootstrap Modal - Return to modal if user does not enter correct field information - asp.net-mvc

Question

I have a contact form in a Twitter Bootstrap Modal and if the user happens to not enter a name or email address and hits submit I want to return to the Modal instead of just closing the Modal. Also if the form is valid I would like to let the user know that an we will be contacting them shortly in the same modal. Is this possible?
Here is my controler.
[HttpPost]
public ActionResult Index(Contact model)
{
ViewBag.IsValid = false;
ViewBag.CaptchaError = "";
RecaptchaVerificationHelper recaptchaHelper = this.GetRecaptchaVerificationHelper();
if (String.IsNullOrEmpty(recaptchaHelper.Response))
{
ViewBag.CaptchaError = "The Captcha cannot be empty";
return View();
}
RecaptchaVerificationResult recaptchaResult = recaptchaHelper.VerifyRecaptchaResponse();
if (recaptchaResult != RecaptchaVerificationResult.Success)
{
ViewBag.CaptchaError = "The Captcha was incorrect";
return View();
}
if (ModelState.IsValid)
{
SendSupportEmail(model);
ViewBag.isValid = true;
}
return View();
}
Here is my view with the Modal
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content col-md-12">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
<h4 class="modal-title" id="myModalLabel">Contact Us</h4>
</div>
<center>
<div class="modal-body">
#using (Html.BeginForm())
{
if ((bool)ViewBag.IsValid)
{
}
else
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<div class="form-group">
<div class="col-md-12">
#Html.TextBoxFor(model => model.Name, new { #class = "form-control", placeholder = "Name" })
#Html.ValidationMessageFor(model => model.Name)
</div>
</div>
<div class="form-group">
<div class="col-md-12">
#Html.TextBoxFor(model => model.Phone, new { #class = "form-control", placeholder = "Phone" })
#Html.ValidationMessageFor(model => model.Phone)
</div>
</div>
<div class="form-group">
<div class="col-md-12">
#Html.TextBoxFor(model => model.Email, new { #class = "form-control", placeholder = "E-Mail Address" })
#Html.ValidationMessageFor(model => model.Email)
</div>
</div>
<div class="form-group">
<div class="col-md-12">
#Html.TextAreaFor(model => model.Comments, new { #class = "form-control", height = "40", placeholder = "Comments" })
#Html.ValidationMessageFor(model => model.Comments)
</div>
</div>
<div class="form-group">
#if (!string.IsNullOrEmpty(ViewBag.CaptchaError))
{
<span class="field-validation-error">#ViewBag.CaptchaError</span>
}
#Html.Recaptcha(theme: Recaptcha.Web.RecaptchaTheme.Clean)
</div>
<div class="form-group">
<div class="col-md-12">
<input type="submit" id="submit" value="Submit" class="btn btn-default btn-lg btn-primary col-sm-12" />
</div>
</div>
</div>
}
}
</div>
</center>
</div>
</div>
I have searched everywhere and was unable to find a solution.

Answer 1

Don't have enough rep to comment - hence the answer. I reckon the easiest way to do this would be to use ajax. User jquery validation plugin to validate user input on submit click. This way, the validation messages can be displayed on the modal itself and the page doesn't have to be refreshed.
On successful validation, the form can be posted to your controller action. You can send a success message as part of your response and display it as a popup or a notification using notifyjs or your own code.