Writing flow logic program lines in Samrtforms..

Hi,

I am working on smartforms.

In general attricutes of field of a particular text, I have to print a field as follows:

Date: &AENR-DATUV&

-

Now if Date is 00/00/0000 then it should print NA instead

of 00/00/0000.

I know I have to write logic in flow logic -> program lines.

IF AENR-DATUV = '00/00/0000'.

W_DATE = 'NA'. (Here the data type of W_Date is char)

ELSE.

W_DATE = AENR-DATUV.(Here the data type is DATS)

Then, declare field as follows in general attributes of text.

Date: &W_Date&

So how do I declare the data type of w_date in global definitions since the data type changes according to value of AENR-DATUV.

Tushar.