Problem setting the focus on a field using actionFunction?

I am trying to reset the focus to the barcode field after a bar code has been entered with a tab as its last character (testing this manually right now). The actionFunction is being called, but the focus is not back on the bar code field after a bar code is entered; the focus is on the field below it. Can someone help me figure this out? Thanks.

<apex:page standardController="Contact" extensions="PhoneAThonScanController" title="Phone-A-Thon Entry">
<apex:form >
<apex:pageMessages id="msgs"/>

    <script language="javascript" type="text/javascript">
        function stopRKey(evt) {
           var evt = (evt) ? evt : ((event) ? event : null);
           var node = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
           if ((evt.keyCode == 13) && (node.type=="text")) {return false;}
        }

        document.onkeypress = stopRKey; 
    </script>

    <apex:actionFunction name="resetFocus" focus="barCode" action="{!scanBarCode}" reRender="block,cons,msgs" />

    <apex:pageBlock title="Inventory Item Receipt" id="block">
          <apex:pageBlockButtons >
              <apex:commandButton action="{!Cancel}" value="Cancel" 
                  onclick="return confirm('Unsaved contacts will be lost.  Are you sure you want to cancel?');"
                  immediate="true" rendered="{!contacts.size > 0}"/>
              <apex:commandButton action="{!cancel}" value="Cancel" immediate="true" rendered="{!contacts.size = 0}"/>
              <apex:commandButton action="{!save}" value="Save" rendered="{!contacts.size > 0}"/>
          </apex:pageblockbuttons>
          <apex:outputPanel id="panel" > 
            <apex:outputText value="Bar Code  " rendered="{!readyToScan}" />
            <apex:inputText value="{!barCode}" rendered="{!readyToScan}" onchange="resetFocus()" id="barCode"/>
     <!--           <apex:actionSupport event="onchange" action="{!scanBarCode}" rerender="cons,msgs,block"/>  -->

            </apex:inputText>
          </apex:outputPanel>
          <br></br>
          <br></br>

          <apex:repeat value="{!$ObjectType.Contact.FieldSets.Contact_Scan_Fieldset}" var="field">
              <apex:outputText value="{!field.label}  " />
              <apex:inputField value="{!newContact[field]}" >
                  <apex:actionSupport event="onchange" action="{!checkContact}" />
              </apex:inputField>
              <br></br>
          </apex:repeat> 
          <br></br>
          <br></br>

          <apex:outputText value="Ready To Scan  " />
          <apex:inputCheckbox value="{!readyToScan}" >
              <apex:actionSupport event="onchange" rerender="panel" />
          </apex:inputCheckbox>
     </apex:pageBlock>

     <apex:outputPanel id="cons" >
     <apex:pageBlock rendered="{!contacts.size > 0}">
        <apex:pageBlockTable value="{!contacts}" var="con" >
            <apex:facet name="header">
                <apex:outputText value="Contacts Added To The Batch" />
            </apex:facet>

            <apex:column >
                <apex:outputField value="{!con.Bar_Code__c}" />
            </apex:column>
            <apex:column >
                <apex:outputField value="{!con.firstName}" />
            </apex:column>
            <apex:column >
                <apex:outputField value="{!con.lastName}" />
            </apex:column>
        </apex:pageBlockTable>
     </apex:pageBlock>
     </apex:outputPanel>

</apex:form>
</apex:page>