I am using a datatable with both sorting and filtering. When I click on a inputText to enter a filtering criteria, it directly sorts the datatable by the selected column. Here is the xhtml code. How can I prevent that the datatable will be sorted when I click on the inputtext?

<rich:column filterExpression="#{fn:containsIgnoreCase(gate.serial, gateListAction.selectorSerial)}" sortBy=

"#{gate.serial}">

<f:facet name="header">

      <h:inputText value="#{gateListAction.selectorSerial}" id="inputSerial">

      <a4j:support event="onkeyup" reRender="gateList" requestDelay="500" oncomplete="setCarriageToEnd(event);"/>

</h:inputText>

</f:facet>

<h:outputText value="#{gate.serial}" />

</rich:column>