checkbox and requiredfieldvalidator

I want to add to the CreateUserWizard an "Accept Terms" checkbox.  I can't use a "RequiredFieldValidator" to ensure the box is checked (unless I'm missing something).  After searching and I came accross this thread: http://forums.asp.net/t/1102440.aspx  
Is this the best way to make a checkbox required? Or is there something else that can be done?
Thanks. 
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