Message Mapping : Display Queue

Hello,

I am trying to get a corresponding value in one segment for a value present in the same segment but in a different field.

E1EDKA1.PARVW values are 'AG','RE','LF','WE',

Corresponding

E1EDKA1.ORT01 values are null,'ABC',null,'XYZ'.

and i require the value of 'WE' so i have my mapping laid out in this way:

if E1EDKA1.PARVW = 'WE' then

i am checking if ORT01 exists are not and if exists then i get the value of E1EDKA1 if not a constant '[]'.

If i have values in all the E1EDKA1.ORT01 then i am getting the correct correspoding value of 'WE' which is 'XYZ'

but if i don't have all the values then its returning the constant '[]'.

How can i return the corresponding value of 'WE' if i don't values for all the fields in ORT01?

TIA,

Jerry