SELECT 1
SELECT MAX(billno) from mstr INTO ARRAY laAarray
IF _TALLY > 0
thisform.text1.value=(RIGHT(STR(YEAR(DATE()),4),2) + '_'+RIGHT(STR(10000+laAarray+1,5),4))+1
ELSE

* Here array laAarray does not exist!! But you want to start from 1?

THISFORM.TEXT1.VALUE = (RIGHT(STR(YEAR(DATE()),4),2) + '_'+RIGHT(STR(10000+1,5),4))
ENDIF