title: Using negation in disabled attribute of h:selectBooleanCheckbox
body: <p>Could someone please tell me how to use negation in the value of a component say checkbox to enable and disable it?</p>
  
  <p>I have to disable a checkbox when the value of a property (somevalue) in bean is false.</p>
  
  <p>like in </p>
  
  <pre><code>&lt;h:selectBooleanCheckbox id="smthing" disabled="#{!somevalue}"&gt;&lt;/h:selectBooleanCheckbox&gt;
  </code></pre>
  
  <p>For bean property</p>
  
  <pre><code>boolean somevalue;
  </code></pre>
  
  <p>should be diabled but it doesnt work. Maybe I am doing something wrong.</p>
  
  <p>Also could someone please clarify if no value is assigned to the boolean what will be the case then.</p>