Good morning, everyone

I have the following issue.

I am trying to create a JS button that will update a few fields on the current object, as well as make a few updates on two related objects.  Here is their relation:

Recruiting Position
Personnel Management ---related to--> Recruiting Position via lookup ID
User Provision Requests ---related to--> Personnel Management via lookup ID

so it works like this:  User Provision Requests --->  Personnel Management ---> Recruiting Position

What I am trying to do is place a button on the User Provision Requests page  that would access a field on the Recruiting Position page and make a change.  I have already been able to make the correct ID calls for update on the User Provision Request and Personnel Management objects, but I am not having any luck with the recruiting position field.  Here's my code, which should explain what I am trying to do:
 

{!REQUIRESCRIPT("/soap/ajax/31.0/connection.js")}

try{
var PersonnelToUpdate = new sforce.SObject("Personnel_Management__c");
var PositionToUpdate = new sforce.SObject("Recruiting_Position__c");
var ProvisionToUpdate = new sforce.SObject("User_Provision_Request__c");

PersonnelToUpdate.Id = "{!User_Provision_Request__c.Employee__c}";
PersonnelToUpdate.Recruiting_Stage__c = "Former Employee";
PositionToUpdate.Id = "{Personnel_Management__r.Recruiting_Position__c.id}";
PositionToUpdate.Recruiting_Stage__c = "Open";
ProvisionToUpdate.Id = "{!User_Provision_Request__c.Id}";
ProvisionToUpdate.Provisioning_Request_Type__c = "Deactivate User Request Form (DURF)";

var result = sforce.connection.update([ProvisionToUpdate]);
var result = sforce.connection.update([PersonnelToUpdate]);
var result = sforce.connection.update([PositionToUpdate]);


if(result[0].success == "true"){
location.reload();
}
else{
alert(
"An Error has Occurred. Error: " +
result[0].errors.message
);
}
}
catch(e){
alert(
"An Error has Occurred. Error: " +
e
);
}

The Recruiting Position ID call is what is failing.  The personnel management and user provision requests calls/actions work just fine.  Any tips as to who I can call on a related field through a shared object?  I want to hop through a lookup field to an object that has an additional lookup field to have access to a 3rd object that contains the fields I want to update.

Your help is greatly appreciated!

Thank you in advance.

Scott