C# - Dynamically Growing Text Fields?

What's the best way to approach the following situation in asp.net mvc2 (c#):I have a form where a user can add more fields ... for example I ask user the details of personal computing devices that they have. For simplicity sake let's say I ask for the brand and type (dropdown list of Desktop/Laptop/Tablet/Other) and they can provide unlimited devices. I will start with a pair of text boxes:

<label>Type</label>
<select><option>Desktop</option><option>Laptop</option><option>Tablet</option><option>Other</option></select>
<label>Brand</label>
<input type="text" />
<input type="button" value="Add more device" />

And then as user click the "Add more device" button I will display another pair of Brand and Type text boxes ... and so on.My question is how should I use HTML helper for this, how I construct the viewModel, etc.I am from PHP background and I used to use the following in PHP:

<input type="text" name="brand[]" />

which on the back end will give me an array of brands ... not sure if that's doable in asp.net environment. I would appreciate any input.[I added the following lines to make my question clearer]
I think I have not been very clear with my question.Suppose I have the following viewmodel:

public class UserRegisterViewModel
{
public string DeviceBrand { get; set; }

[code]...