Issue with overlay

Hi

I have a requiremnet wherein the user enters data from the footer record format, and this gets written in the subfile above the footer -


MODE : ADD Vendor Number : Buyer : Address Contract No.: - This field is updateable

Subfile Control Format
------------------------------------------------------------------------------------------ Period Quantity Price Line From To Product U/M Per U/M Subfile Record Format ------------------------------------------------------------------------------------------ Footer Record Format
Line Period : 0/00/00 to 0/00/00 Product : Qty : .000 U/M : Price PerU/M : .000 ENTER=Accept Line F2=Cancel F3=Fold F4=Delete F5=Accept F14=Maintain Notes


Whenevr the user enters data in the footer, after all validations it is written to the subfile
Since i also have to perform validations for header
my condition was as follows(i.e perform Header fields are only validated while writing a new record)
While writing a new record(Header )
Check if all the header fields are valid
If not valid i.e. error in Header
Write SFLCTL
Write Footer
Else
Write SFLCTL
Exfmt Footer
Endif

If Error in header
Read SFLCTL
Read Footer
Endif


Everything was working fine, until now, when the requirement has changed and the fields in the Header(Subfile Control) are also updateable. Now i am finding difficulty to toggle beween reading the subfile control and the footer to perform validations
I was wondering if the following is possible i.e. have the Header fields also in the Footer Record format
Can this be managed by OVERLAY? i.e. is it possible to display the subfile in this manner

MODE : ADD Vendor Number : Buyer : Address Number : - This field is updateable

Footer Record Format
------------------------------------------------------------------------------------------ Period Quantity Price Line From To Product U/M Per U/M

Subfile Control------------------------------------------------------------------------------------------ Subfile Record Format ------------------------------------------------------------------------------------------ Footer Record Format
Line Period : 0/00/00 to 0/00/00 Product : Qty : .000 U/M : Price PerU/M : .000 ENTER=Accept Line F2=Cancel F3=Fold F4=Delete F5=Accept F14=Maintain Notes



Thanks in advance for all your suggestions

Derek