Dear Experts,
In our navision 2016. we are using the approval process but in sales return order not using approval process so thats reason "Reopen" btn is not working. How can I enable in sales return order page. I have write the code in "Reopen" btn but it is not working. Please suggest me, how it will work. My written code is below:

IF SalesHeader."Document Type"=SalesHeader."Document Type"::"Credit Memo" THEN

Also I have write the same code in codeunit 414 but there is no effect. What I am doing wrong.