如何将文本框值传递给控制器

I have a textbox like below

我有一个像下面这样的文本框

   @using (Html.BeginForm("checkUserType", "Place", new {type =  }))
    {
        <div id="login">
            <div class="userNameLabel">UserName</div>
            <div class="userNameField"><input type="text" id="txtUserName"/><span><input type="button" value="ok" id="ok" /></span></div>
        </div>
    }