### Options:
- value - the value of the checkbox
- checked - boolean indicate that this checkbox is checked.
- hiddenField - boolean to indicate if you want the results of checkbox() to include
a hidden input with a value of ''.
- disabled - create a disabled input.
- default - Set the default value for the checkbox. This allows you to start checkboxes
as checked, without having to check the POST data. A matching POST data value, will overwrite
the default value.