(Quick Reference)
                checkBox
Purpose
Generates a checkbox form field. All the usual HTML elements apply.
Examples
<g:checkBox name="myCheckbox" value="${true}" />Description
Attributes
- name- The name of the checkbox
- value(optional) - The value of the checkbox
- checked(optional) - Expression if evaluates to- truesets to checkbox to checked
The 
checkBox tag typically only requires the 
name and 
value attributes and will infer whether the checkbox should be checked from the value. The 
checked attribute can be used to override this behaviour for fine-grained control.
Source