Thank u for your Reply Nagarajan K
that happend only in the following case
but when is checked, it not only opens sales order when return/cr note created but also update the delivered qty field but when quantity is fully return i.e. delivered 100 out of 100 when return created it opens so and updated delivered qty field with 0 but it not happens in partial dn case i.e. 50 out of 100 so in del qty field it shows 50 but when return created its not change to 0 however SO remains open and it should be
hope you understand it
Regards
Jamil