Save each page of a multi-page document as a separate file using spawned file names with javascript

Question

Hello
We are currently changing our hard-copy personnel files and converting them to pdf files.  We have scanned the entire file into one multi-page document.
I am wanting to save each page (or groups of pages) as separate files.
In order to facilitate this, I have duplicated field names--such as FirstName, LastName, EmpNo on each page.  This information should be static for the entire file.
However--I also need information that will change for each individual "page" or document--such as TypeOfDoc, Date, etc.  I have used the Spawn fields using the overlay method on each of the pages in the document.  Then I went in and filled in the information for each page of the document--such as TypeOfDoc, DateOfDoc.
Now I want to save each page of the document as a separate file using the field names as the file name.
I first created an action that would split all the pages into separate files and save them into a folder.
Then I want to save each file as a specific file name based on the information in the fields.
My problem is obtaining the name of the spawned field name.  The rest of the field names I am not having a problem with.
This is what I have so far to name the file.
// Get the field value
var oPage = this.pageNum;
var fn = getField("P" + oPage + ".TEMPLATE.DateOfDoc").valueAsString + getField("FirstName").valueAsString + "-" + getField("LastName").valueAsString;
// Specify the folder
var fldr = "/n/Personnel/ScannedDocuments/NAMEDPAAS/";
// Determine the full path
var fp = fldr + fn +".pdf";
// Save the file
myTrustedSpecialTaskFunc(this, fp);
This code is also accompanied with folder level scripts.
My problem is obtaining the name of the spawned fields using javascript.  Each document has several pages--so I would like to obtain the field name through script.
I receive the following error.
TypeError: getField("P" + oPage + ".TEMPLATE.DATE") is null
I think this is due to the fact that I have extracted all the pages as individual files.
If I were to do the above, but not extract the pages first--I do not know how to just save one page at a time.
Please help.  This is a massive project, and if we have to save each file individually, it will take a lot of time.
I am a beginner, so any assistance is appreciated.
Thank you

Answer 1

I am not understanding exactly where to put the curly brackets.  I have tried two different ways, and still get the same error.
This is one way
var oPage = this.pageNum;
// Specify the folder
var fldr = "/n/Personnel/ScannedDocuments/NAMEDPAAS/";
// Determine the full path
var fp = fldr + fn +".pdf";
for (var i = 0; i < this.numPages; i++) 
var fn = getField("P" + oPage + ".template.DateOfDoc").valueAsString + getField("FirstName").valueAsString + "-" + getField("LastName").valueAsString;
{this.extractPages({  
nStart: i,  
cPath : fldr + fn + ".pdf"
The other is this
var oPage = this.pageNum;
// Specify the folder
var fldr = "/n/Personnel/ScannedDocuments/NAMEDPAAS/";
// Determine the full path
var fp = fldr + fn +".pdf";
for (var i = 0; i < this.numPages; i++) 
var fn = getField("P" + oPage + ".template.DateOfDoc").valueAsString + getField("FirstName").valueAsString + "-" + getField("LastName").valueAsString;
this.extractPages({  
nStart: i,  
cPath : fldr + fn + ".pdf"
Thank you for your help.