I need to use the actionFunction tag to  launch a controller method.
The controller method returns a new page reference. However it seems my controller method is not called...
MIRPriorityDetails is my component with some proprties.

VF:

<apex:page title="CEB - MIR Home Page" standardcontroller="CC__c" extensions="CCController" action="{!MIRContactCreation}">
<apex:includeScript value="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></apex:includeScript>
<script type="text/javascript">
function saveVertical(e,type){
                window['savepriorityDetail'](<input>);
            }

function resetAction(){}
</script>
<apex:PageBlokButtons>
<input type="button" class="btn mirsave mirbtn" value="Save" onclick="javascript:saveVertical(this,'priorityDetail');"/>
</apex:PageBlokButtons>      
<c:MIRPriorityDetails p="{!priority}" showExtra="{!MIR.hasMainSA}" hidebut="{!isedit}" />
</apex:page>

Component:

<apex:component controller="MIRPriorityDetailController" allowDML="true">
  <apex:actionFunction name="savepriorityDetail" action="{!SavePriority}" oncomplete="resetAction();">
        <apex:param value="aoe" name="aoe" assignTo="{!areasOfExpertise}"/>
    </apex:actionFunction>

</apex:component>

component Controller:
public class MIRPriorityDetailController {

public pageReference SavePriority(){       
        try{
            update sobj;
            PageReference pageRef = new PageReference('/apex/HelloWorld');
      pageRef.setRedirect(true);
      return pageRef;
        }
        catch(Exception excp){

             ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.FATAL, 'There are already 5 active priorites and please inactive one to activate the new prority.');
             apexpages.addmessage(myMsg);
        }
        return null;
    }
}