hi,
thank you very much,
it works. but still i need to replace only the new data with old data,not append all data, if i run the program ex.. 5 times ,and i have somthing as 10 records at xldata,thats mean i have 50 records at nan.dbf ,just i need new 10 records at nan.dbf.every time i run myprogram.

USE xldata in 0
USE nan in 0
DELETE ALL fields EXCEPT char19&& how i can do this
select xldata
SCAN
   SCATTER memvar 
   *!* either append blank or seek correct record to update
   SELECT NAN
   *append blank
   && i need to replace (delete all data replace new data)
replace all
   GATHER memvar field EXCEPT char19
ENDSCAN

thanks.
best regards.
m.qasem