将数据从视图传递到控制器(MVC 3)

当我试图将字符串从视图传递到控制器时，我的ASP.NET应用程序出现问题。。。

我的控制器（需要的方法）

`public ActionResult Mail(int id) //Display the View "Mail"
    {
        Customer customer = db.Customers.Find(id);
        return View(customer);
    }
    [HttpPost,ActionName("Mail")] // this Method allow to send a email
    public ActionResult MailConfirmed(int id)
    {
        Customer customer = db.Customers.Find(id);
        string message = Request.Form.Get("messageBody");//Here I try to recuperate my messageBody
        if(message!=null)
        {
            System.Diagnostics.Debug.WriteLine(message);
            SendMail(customer.Mail, customer.Name, message);
            return RedirectToAction("Index");  
        }
        else
        {
            ModelState.AddModelError("", "Veuillez rentrer un message SVP"); 
        }
        return View(customer);
    }`

查看"邮件"（经理可以在其中输入邮件正文并单击"邮件"发送邮件的页面）

'@using (Html.BeginForm())
  {
   <fieldset>
       <legend>Customer</legend>
       <div class="display-label">Pin</div>
       <div class="display-field">
           @Html.DisplayFor(model => model.Pin)
       </div>
       <div class="display-label">Name</div>
       <div class="display-field">
           @Html.DisplayFor(model => model.Name)
       </div>
        etc...
       <div class="display-field">
           @Html.TextBox("messageBody",null)//here the value that I try to pass in my controller
       </div>

   </fieldset>
  }
  @using (Html.BeginForm())
 {
 <p>
     <input type="submit" value="Mail" />
    <div>
        @Html.ActionLink("Back to List", "Index")
    </div>
 </p>
  }`    

"消息"始终为空。。。你能帮我吗

[HttpPost,ActionName("Mail")] // this Method allow to send a email
    public ActionResult MailConfirmed(int id, string messageBody)
    {
        Customer customer = db.Customers.Find(id);
        if(messageBody!=null)
        {
            System.Diagnostics.Debug.WriteLine(messageBody);
            SendMail(customer.Mail, customer.Name, messageBody);
            return RedirectToAction("Index");  
        }
        else
        {
            ModelState.AddModelError("", "Veuillez rentrer un message SVP"); 
        }
        return View(customer);
    }