private void SetDocIndexValue(ref AssociatedDoc assDoc)
        {            
            AssociatedDocsDal assocDocsDal = new AssociatedDocsDal(sqlConnectionString);
            int inboundDocsId = Convert.ToInt32(assDoc.InboundDocsId);
            int indexVal = assocDocsDal.GetCurrentIndexValue(inboundDocsId);

            if (indexVal >= 0)
            {
                assDoc.IndexVal = indexVal + 1;
            }
            else
            {
                throw new Exception("An error occurred while setting the document index value." + Environment.NewLine +
                        "Error CNF-513 in " + FORM_NAME + ".SetDocIndexValue().");
            }            
        }