set_checkbox after form validation

[eluser]Wonder Woman[/eluser]
Hi,

I have a checkbox which has a null value, which I would like to be 0 and when the user clicks on it for it to change to 1.

I have form validation set up but when the form is repopulated with the sent form data the checkbox does not change.

If anyone can help me that would be great.

Code:

echo form_label('Anonymous', 'anonymous');
echo form_checkbox('anonymous', set_checkbox('anonymous'), FALSE);

Thanks!