Please help: Populating values in drop down list by onchange - javascript !

Question

I am working on a task - I need to populate drop down named "year" dynamically (from database) depending upon the select of an element from drop down list "carLine" . I am calling javascript funtion on onchange event of the html select and setting property of the selected element.The environment is Struts and dynaactionform is being used . Here is the my html select for both the drop down list s and javascript funtion to set value. The getYears method is defined in the locatoraction action class. But after doing all these carLine is not getting populated with the values corresponding to selected carline.
Database side is working fine .
<script type="text/javascript">
function getYearsForCarline(){
document.getElementById('method').value = 'getYears';
document.forms[0].submit();
alert("submitted");
</script>
<html:form styleId="locatorForm" action="/locator/locatorAction" method="post">
          <input type="hidden" name="method" value="getYears" />
          <tr>
               <td align="center">
               <table border="0" width="300" cellpadding="0" cellspacing="5">
                    <tr>
                         <td><span class="formLabelEM"><bean:message
                              key="label.locator.carLine" />*</span>
                         <html:select styleId="carLineBox" property="carLine" onchange="javascript:getYearsForCarline()">
                              <html:option value="">Select a Carline</html:option>
                              <html:optionsCollection property="carLines" />
                         </html:select></td>
                    </tr>
                    <tr>
                         <td><span class="formLabelEM"><bean:message
                              key="label.locator.modelYear" />*</span>
                         <html:select property="year" >
                         <html:option value="">Select Year</html:option>
                              <html:optionsCollection property="years" />
Any advise will be highly appreciated . Thanks in advance.

Answer 1

Thanks both of you for the advise ! My code worked perfectly fine after adding separate action mapping for Year and using that as action in the form though the new action mapping point to the same action class locatorAction ..I still do not understand the reason behind this exactly(any suggestion are most welcome) but it works. Here is code for my action mapping :
<action path="/locator/locatorYearAction" name="locatorForm"
               input="/locator/locatorMain.jsp"
               type="com.apps.sales.web.salesin.actions.LocatorAction"
               parameter="method" validate="true">
               <forward name="showCarlines" path="/locator/locatorMain.jsp"
                    redirect="false" />
               <forward name="showModels" path="/locator/locatorModels.jsp"
                    redirect="false" />     
          </action>