Activation Form for C#

I'm hoping to use LimeLM in a C# Autocad plugin, and it turns out I can't call an external exe the way the plugin is structured. I'll need to roll my own modal form and prompt the user for an activation code. Is there a good example for me to follow?

Prompting for a product key and then activating is fairly simple. All you really need for a simple activation form is a simple text box for the product key and a button to activate the key. Then simply call CheckAndSavePKey() to verify and save the user-entered product key and use Activate() to actually activate the product key.

Thanks Wyatt, that's perfect, got it up and running.