Partial View models - asp.net-mvc

Question

Within my layout page, I want to either show a Login box, OR the details about the logged in person.
<div>
#if (Request.IsAuthenticated)
{
#Html.ViewBag.UserDisplay
#Html.ActionLink("[Logout]", "LogoutUser", "User")
}
else
{
#Html.Partial("_Login")
}
<hr />
#RenderBody()
</div>
My login partial view:
#model BasicFinanceUI.Models.LoginModel
#using (Html.BeginForm("LoginUser", "User"))
{
#Html.ValidationSummary()
<p>
Username: #Html.TextBoxFor(x => x.Username)
Password: #Html.TextBoxFor(x => x.Password)
Remember Me: #Html.DropDownListFor(x => x.RememberMe, new[]
{
new SelectListItem() { Text = "Yes", Value = "true"},
new SelectListItem() {Text = "No", Value = "false"}
}, "Select")
<input type="submit" value="Login" />
#Html.ActionLink("[Register]", "Register", "User")
</p>
}
When I load the screen, and login, it works fine.
However, when I click 'Register', it loads the register screen. The login box is still visible in the Layout.
My registration screen is displayed:
#model BasicFinanceUI.Models.RegisterationModel
#{
ViewBag.Title = "Register";
Layout = "~/Views/Shared/SiteLayout.cshtml";
}
<h2>Register</h2>
#using (Html.BeginForm("Register", "User"))
{
<p>#Html.ValidationSummary()</p>
<p>Username: #Html.TextBoxFor(x => x.Username)</p>
<p>Password: #Html.PasswordFor(x => x.Password1)</p>
<p>Retype Password: #Html.PasswordFor(x => x.Password2)</p>
<p>Firstname: #Html.TextBoxFor(x => x.Firstname)</p>
<p>Surname: #Html.TextBoxFor(x => x.Surname)</p>
<p>Email: #Html.TextBoxFor(x => x.Email)</p>
<p><input type="submit" value="Register"/></p>
}
When I click the Register button, things go wrong.
I get the error:
The model item passed into the dictionary is of type
'BasicFinanceUI.Models.RegisterationModel', but this dictionary
requires a model item of type 'BasicFinanceUI.Models.LoginModel'.
It seems because there are two forms on the screen, they're getting mixed up. What am I doing wrong?