title: How use <p:calendar> correctly?
body: <p>I'm trying to do a <code>search</code> method, for that I use two dates, <code>checkin</code> and <code>checkout</code>.
  I'm starting to use <code>primefaces</code> some days ago.</p>
  
  <p>So at <code>search.xthml</code> I have:</p>
  
  <pre><code>&lt;h:form id="search_form" styleClass="searchform"&gt;
    ..
        &lt;p:calendar id="checkin" beforeShowDay="false" pattern="dd/MM/yyyy" readonly="true" readonlyInput="true" effect="drop" showButtonPanel="true" navigator="true" locale="pt" mindate="#{systemC.today}" value="#{systemC.checkin}"&gt; 
          &lt;p:watermark for="checkin" value="Check-in"  /&gt;  
        &lt;/p:calendar&gt;
  
        &lt;p:calendar id="checkout" beforeShowDay="false" pattern="dd/MM/yyyy" readonly="true" readonlyInput="true" effect="drop" showButtonPanel="true" navigator="true" locale="pt" mindate="#{systemC.today}" value="#{systemC.checkout}"&gt; 
          &lt;p:watermark for="checkout" value="Check-out"  /&gt;  
        &lt;/p:calendar&gt;
    ..
  &lt;/h:form&gt;
  </code></pre>
  
  <p>At my bean, <code>SystemControl</code> I have:</p>
  
  <pre><code>@ManagedBean(name="systemC")
  @SessionScoped
  public class SystemControl  implements Serializable{
      private static final long serialVersionUID = 8454359216475311220L;
  
      private Message message;
  
      private String search;
      private Date checkin;
      private Date checkout;
      private Integer guests;
  
      private Date today;
  
      public String doSearch(){
          System.out.println(search + " " + checkin + " " + checkout + " " +guests);
          return null;
      }
      ..
  </code></pre>
  
  <p>The problem is that, everytime I call the method <code>doSearch</code>, both, <code>checkin</code> and <code>checkout</code> are <code>null</code>.
  I already look into <code>primefaces</code> showcase but still look right what I'm doing here to me.</p>
  
  <p>What I'm missing here ? Any idea ? Any suggestion ?</p>