Meaning of MASK(NNNNNNN) statement?

[diptisaini]

DEFINE DATA LOCAL
1 #CURRENT-ASSET-HOLDING (A11)
1 REDEFINE #CURRENT-ASSET-HOLDING
2 #T-ENT (A3)
2 #CURRENT-HOLDING (A1)
2 #T-ASS (A7)
2 REDEFINE #T-ASS
3 #T-ASS-N (N7)
END-DEFINE
IF #T-ASS = MASK(NNNNNNN)

what is the meaning of IF #T-ASS = MASK(NNNNNNN) statement ? Can anyone explain me ?

[RGZbrog]

MASK is used in a logical condition to test the contents of specific bytes of an alpha variable. Each N in the mask checks the corresponding byte position for a Numeric value. So, the IF statement is asking "Does #T-ASS contain 7 numeric digits?"

A complete description is provided here: http://documentation.softwareag.com/nat ... ASK_Option