h:selectOneMenu with ajax support

[chicco0386]

Hi, I'm try to use the ajax support inside an h:selectOneMenu, but it doesn't work.
This is my piece of code:

<rich:column styleClass="action">
    <h:selectOneMenu value="#{processo.arcoTemporale}">
      <f:selectItem itemLabel="10 minuti" itemValue="10" />
      <f:selectItem itemLabel="20 minuti" itemValue="20" />
      <f:selectItem itemLabel="30 minuti" itemValue="30" />
      <f:selectItem itemLabel="40 minuti" itemValue="40" />
      <f:selectItem itemLabel="50 minuti" itemValue="50" />
      <f:selectItem itemLabel="1 ora" itemValue="1" />
      <a4j:support event="onchange" reRender="text" />
     </h:selectOneMenu>
    <h:inputText id="text" value="#{processo.arcoTemporale}" />
</rich:column>

{processo.arcoTemporale} is a String.

Can you help me please?

Thank you.