set default selected value in struts2 select tag

      <!--name attribute inside select tag must be a variable in action class with getter/setter -->  
      <!-- test variable sets the value of selected item in action class -->  
      <select name="test">  
           <!-- name attribute could be anything you want but value attribute must be a model class variable-->  
           <s:set name="lead_string_LS_ID" value="MasterDataModel.string_LS_ID" />  
                <!-- value attribute must be a list to iterate, status (an instanceof IteratorStatus will be pushed into stack upon each iteration)or result -->  
                <!-- var Name used to reference the value pushed into the Value Stack (my list contain leadSource_String_Id)-->  
                <s:iterator value="leadSource_list" status="result" var="leadSource_String_Id">  
                          <!--#lead_string_LS_ID is value taken from <set> tag above. Note # must be in-front of the name  
                               leadSource_String_Id is element specified in var of <iterator> tag       
                          -->  
                          <s:if test='(#lead_string_LS_ID.equals(leadSource_String_Id))'>  
                               <option value="<s:property value='leadSource_String_Id'/>" selected="selected">  
                                    <s:property value="leadSource_String_Name" />  
                               </option>  
                          </s:if>  
                          <s:else>  
                               <option  
                                    value="<s:property value='leadSource_String_Id'/>">  
                                    <s:property value="leadSource_String_Name" />  
                               </option>  
                          </s:else>  
                </s:iterator>  
      </select>