Excuse me for not describing my setup earlier: 1> Tomcat 6.0 2> Embedded Jboss: embedded-jboss-beta2 3> JDK 1.5.0_12-b04 4> Interestingly my page source has action empty : | <a4j:support event="onchange" action="" ajaxSingle="true"></a4j:support> | <select id="j_id2:dataTransferCombobox" name="j_id2:dataTransferCombobox" size="1"> <option value="PLAIN_TEXT">PLAIN_TEXT</option> | <option value="SRB_ENCRYPT" selected="selected">SRB_ENCRYPT</option> | <option value="KERBEROS_INTEGRITY">KERBEROS_INTEGRITY</option> TIA RAVI View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4066840#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...