window possible with internally described dspf?

Hi,

I have an old rpgIII with its dspf records internally described. I specs and EXCPT with O specs.

I don't know if there are many ways of identifying each record to the program as I have never much worked with a file described like this.

Each record has an input only field of one character like so :
A FA0001 1A I 1 2DFT('Y')
A DSPATR(PR)
A DSPATR(ND)
A DSPATR(MDT)

In the program I specs I have :
ISCREEN NS 1 CA
I 2 8 ECINS7
I 9 38 ECNOMA
I 39 68 ECPREA

and
ISCREEN NS 1 CY
I 2 11 etc;

In the DSPF, I've added two window records. I added a unique character field in the same way the other records are declared in the above example. The first window has the window dimensions, position and title (P zone). The second has the first window as it's window parameter.

I declared them in the rpg so :
I* FORMAT-ADHC00W1 reference window
IECRAN NS 1 CW
*
I* FORMAT-ADHC0022 window with user field
IECRAN NS 1 CY
I 2 2 EECFFL


Now when I try to write the window :
C MOVEL'test' EWDWLB 76 P P zone in reference window dds
C MOVEL'O' EECFFL Output zone in window dds
C EXCPTCREW1
C EXCPTCRE22



OECRAN E CREW1
O EWDWLB 76
OECRAN E CRE22
O EECFFL 1


I get a session error on line
O EWDWLB 76
with RPG1255. It says to refer to the major/minor return code which I can't find.

Any help with dealing with the error message would be great.
Could someone explain this method of identifying record formats? Is it even possible to add a window in this way?

Thanks.