Funcionamiento de los checkboxs en Struts

<html:checkbox property="someprop" value="true">Yes</html:checkbox>

String somepropValue = null;
if((somepropValue = request.getParameter("someprop")) != null)
{ 
  // ckecked
  Sytem.out.println("The box is checked and its value is " + somepropValue);
}
else 
{
  // not ckecked
  Sytem.out.println("The box is not checked");
  // set the value
  someprop = "false";
}