Hidden Checkbox – Won’t work – pls help!

Hello,

I’ve got one form that is using the following code to check a checkbox “Checked” or “Not Checked” value – and it works fine and is being passed via POST.

[checkbox newsletter_subscription_ id:check-one “Subscribe to our newsletter”]

I’m attempting to use the same field in a separate form, have it be hidden and be default checked, but for the life of me I cannot get it to work. I have tried many variations such as:

[hidden newsletter_subscription_ value=”Checked”]
[hidden newsletter_subscription_ default=1 “Subscribe to our newsletter”]

Any help would be really greatly appeciated.