unable to get the selected value from combo box

[assyst]

I am able to populate the values in a combo box (from corresponding bean) but when i submit the page after selecting a value  from it,an
exception of the following type occurs:

22:48:38,266 ERROR [ExceptionFilter] uncaught exception
javax.servlet.ServletException: For input string: "Infosys"

Please help me to solve this ...


My combo box xhtml code

<h:selectOneMenu  value="#{machineBean.vendorName}" tabindex="4" >
                                                                                               <s:selectItems value="#{vendors}" var="vendorNm" itemLabel="#{vendorNm.vendorName}" itemValue="#{vendorNm.vendorName}" noSelectionLabel="-- Select Vendor --" />
                                                                                               <s:convertEntity/>
                                                                                           </h:selectOneMenu>