Null check in Condition Editor: Interface Determination

Hi All,

I am doing a IDoc -> File Scenario. I want to use 2 different mapping programs depending on the existing of the field /ZDELVRY03/IDOC/E1EDL20/VBELN.

if VBELN exist Mapping1

If VBELN does not exist Mapping2

I tried using the EX operator for the first case, How do we handle the <b>Does not exist</b> condition? If i just leave the condition empty for seond case it gives an error stating Multiple inbound interface found - clearly finding 2 interfaces.

How do i handle DOES NOT EXIST condition??

Any clues??

Pavan.