<table>
    <tr>
        <td>
            UserName:
        </td>
        <td>
            @Html.TextBox("userName")
        </td>
    </tr>
        <tr>
        <td>
            Password
        </td>
        <td>
            @Html.Password("Password")
        </td>
    </tr>
    <tr>
        <td colspan="2">
            @Html.ActionLink("login", "SignIn")
        </td>
    </tr>
</table>

public ActionResult SignIn()
{
    //string userName = Request["userName"];
    return View("Home");
}

@using (Html.BeginForm("SignIn", "Controller", FormMethod.Post, new { id = "form1" }))
{
    <table>
    <tr>
        <td>
            UserName:
        </td>
        <td>
            @Html.TextBox("userName")
        </td>
    </tr>
        <tr>
        <td>
            Password
        </td>
        <td>
            @Html.Password("Password")
        </td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" value="login" name="login" />
        </td>
    </tr>
</table>
}

[HttpPost]
public ActionResult SignIn(FormCollection frmc)
{
    /// Extracting the value from FormCollection
    string name = frmc["userName"];
    string pwd = frmc["Password"];
    return View("Home");
}

@using (Html.BeginForm("SignIn", "controllerName", FormMethod.POST))
{
<table>
...
</table>
<input type="submit" value="Sign in" />
}

[HttpPost]
public ActionResult SignIn(string userName, string Password)
{
 //sign in and redirect to home page
}

@{
ViewBag.Title = "SignIn";
Layout = "~/Views/Shared/_Layout.cshtml";
 }
 @using (Html.BeginForm("Home", "SignIn"))
 {
  <table>
     <tr>
        <td>
            UserName:
        </td>
        <td>
            @Html.TextBox("userName")
        </td>
    </tr>
    <tr>
        <td>
            Password
        </td>
        <td>
            @Html.Password("Password")
        </td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" value="LOgin" />
        </td>
    </tr>
</table>

public ActionResult SignIn()
    {
        return View();
    }

    [HttpPost]
    public ActionResult SignIn(FormCollection form)
    {
        string userName = form["userName"];
        string password = form["Password"];
        return View();
    }