Create Credit note using X++ AX2012

In the below example we are going to create a credit note for a Sale order which is already invoiced.

For this, we need to create a class and add the below method.
In this method, we are getting the data from a temp table mkCreditNote or any other source like CSV, WCF etc.
public void postCreditnote( RecId               _creditnoteRecid)
{
    CustInvoiceTrans        custInvoiceTrans;
    SalesCopying            salesCopying;
    boolean                 isCreditNoteCreated,isCreditNotePosted;
    SalesId                 salesid;
    SalesTable              salesTable;
    MKCreditNote           mkCreditNote;
    TmpFrmVirtual           tmpFrmVirtualHeader;
    TmpFrmVirtual           tmpFrmVirtualLines;

    void loadTmpVirtualTableAndCreateCN(CustInvoiceTrans _custInvoiceTrans,MKCreditNote _mkCreditNote,SalesTable _salesTable)
    {
        delete_from tmpFrmVirtualLines;
        tmpFrmVirtualLines.TableNum = _custInvoiceTrans.TableId;
        tmpFrmVirtualLines.RecordNo = _custInvoiceTrans.RecId;
        tmpFrmVirtualLines.Id = _custInvoiceTrans.SalesId;
        tmpFrmVirtualLines.LineNum = _custInvoiceTrans.LineNum;
        tmpFrmVirtualLines.TransDate = _custInvoiceTrans.InvoiceDate;
        tmpFrmVirtualLines.Qty = _mkCreditNote.Qty;

        tmpFrmVirtualLines.write();

        salesCopying = SalesCopying::construct(SalesPurchCopy::CreditNoteLines);
        salesCopying.initParameters(_salesTable,
                                    tmpFrmVirtualLines,
                                    tmpFrmVirtualHeader,
                                    1,
                                    true,
                                    false,
                                    true,
                                    true,
                                    false);

        salesCopying.copy();
    }

    select firstOnly salesid, RecId from mkCreditNote
    where mkCreditNote.RecId == _creditnoteRecid;
    if (mkCreditNote.RecId)
    {
        salesTable = SalesTable::find(amsCreditNote.SalesId,false);
        if (salesTable.RecId)
        {
            while select amsCreditNote
                join custInvoiceTrans
                where custInvoiceTrans.SalesId == mkCreditNote.SalesId
                && custInvoiceTrans.ItemId == mkCreditNote.ItemId
                && custInvoiceTrans.InventDimId == mkCreditNote.InventDimId
                && custInvoiceTrans.InventTransId == mkCreditNote.InventTransId
                && amsCreditNote.RecId == _creditnoteRecid
            {
                isCreditNoteCreated = true;
                loadTmpVirtualTableAndCreateCN(custInvoiceTrans,mkCreditNote,salesTable);
            }
        }
    }


}