Why does ASP.NET MVC Html.CheckBox output two INPUTs with the same name?

Question

Why in the world does the line:

<%= Html.CheckBox(\"ForSale\", Model.Product.ForSale)%> For Sale

result in the following HTML:

<

Answer 1

I think the cleanest solution is to do:

(bool)formCollection["key"].ConvertTo(typeof(bool))