Uploading program using bdc in fd32 how to restict the uploading value

HI,

      BDC program to uploading the data in fd32 transaction, up to this i done, but i want restict the value credit limit(klimk).

      customer 1 first time iam uploading the 5%, next allow the value 5% only that means only 10 % only allowed, after 10% i want to upload means it will show the error message.

   my dought is in that bdc program data uploading time how to restict the value ? if any method share it.