D365/ Ax2012: X++ code for custom lookup to show customer account and Name

public void lookup()
        {
            Query query = new Query();
            QueryBuildDataSource queryBuildDataSource, qbds;
            QueryBuildRange queryBuildRange;
   
            SysTableLookup sysTableLookup = SysTableLookup::newParameters(tableNum(custTable), this);
   
            sysTableLookup.addLookupField(fieldNum(CustTable, AccountNum));
            sysTableLookup.addLookupField(fieldNum(CustTable, CustGroup));

            sysTableLookup.addLookupField(fieldNum(CustTable, Party), false);

            queryBuildDataSource = query.addDataSource(tableNum(CustTable));

            qbds = queryBuildDataSource.addDataSource(tableNum(DirPartyTable));

            qbds.joinMode(JoinMode::InnerJoin);

            qbds.addLink(fieldNum(CustTable, Party), fieldNum(DirPartyTable, RecId));
   
            sysTableLookup.parmQuery(query);
   
            sysTableLookup.performFormLookup();
        }