Ajuda - Struts 2

<s:form id="crudForm" name="crudForm" action="InserirTema.action" method="POST" enctype="multipart/form-data" >
	<s:hidden id="operation" name="operation" />		

    <s:div id="DadosTema" theme="admix/innerheader" >
    	<s:param name="titulo" ><s:text name="_tema"/></s:param>
		<s:param name="ajuda" >${pageContext.request.contextPath}/helps/noPageHelpFound.html</s:param>
		<s:param name="descricao" ><s:text name="_tema"/> - <s:text name="_inserir"/></s:param>

		<div class="div_content">		
		
			<s:fielderror theme="admix" template="errortable.ftl" cssClass="algum"/>
			<s:actionmessage theme="admix" cssClass="algum"/>
		
			<s:div label="_dados_principais" id="div_dados_principais" theme="admix/block/openclose" cssClass="subpanel_ico_content" onchange="false" cssStyle="contentpanel">

				<table border="0">
					<tr>
						<td><s:text name="_tema"/>:</td>
						<td><s:file name="upload" title="%{getText('_procurar')}" size="50"/>
						<input type="button" onclick="submitAjaxFormMultipart()" />				
						</td>																							
					</tr>					
				</table>				
			</s:div>
												
		</div>
		<s:component theme="admix/buttons" template="barraNavegacao.ftl" />

	</s:div>
</s:form>

function submitAjaxFormMultipart() {

	dojo.io.bind( {
		formNode :dojo.byId('crudForm'),
		mimetype :"text/plain",
		multipart :true,
		handle : function(type, data, e) {
		dojo.widget.byId('DIVStructureBody').setContent(data);			
		},
		error : function(type, data, e) {				
			alert("An error occured!");			
			alert(data.message);					
		}
	});
	
}