Hi, as far as I know there is no direct way. The two documents themselves are not directly related.
However, if you use the Cancel or Correct functions to create and post creditmemo, you can associate it with the Posted Sales invoice number (Applies-to Doc. No. ). If the Credit Memo is created manually and no Invoice is applied, it should not be found.
Hope this can give you some hints.
Thanks.
ZHU
