<action
            path="/MyAction"
            type="MyAction"
            parameter="MyProperty"
            name="MyForm"
            >
            <forward .../>
</action>

<html:form action="/MyAction.do">
             <html:submit property="MyProperty" value="VALUE1" />

            <html:image property="MyProperty" value="VALUE2" src="images/BLBL.jpg" />

</html:form>

 if ("VALUE1".equals(httpServletRequest.getParameter(actionMapping.getParameter()))){
// Делаю одно
}
 if ("VALUE2".equals(httpServletRequest.getParameter(actionMapping.getParameter()))){
// Делаю другое
}