lookup - use method in lookup and

Query       query = new Query();
    QueryBuildDataSource    qbds,qbds1;
    //QueryBuildRange         qbr;
    SysTableLookup          sysTableLookUp; VendTable VendTable ;
    sysTableLookUp = SysTableLookup::newParameters(tableNum(VendTable),_control);
    //qbds = query.addDataSource(tableNum(VendorView));     
    //qbr = qbds.addRange(fieldNum(VendorView, AccountNum));
    //qbr.value(SysQuery::valueNotEmptyString());
    //
    //sysTableLookUp.addLookupfield(fieldNum(VendorView,AccountNum));
    //sysTableLookup.addSelectionField(fieldNum(VendorView,AccountNum));
    //sysTableLookUp.addLookupfield(fieldNum(VendorView,Name));
    //
    //sysTableLookUp.parmQuery(query);
    //sysTableLookUp.performFormLookup();
   
    qbds = query.addDataSource(tableNum(VendTable));
   //qbds1  = qbds.addDataSource(tableNum(DirPartyTable));
   //Qbds1.addLink(fieldNum(VendTable, Party), fieldNum(DirPartyTable, RecId));
   //Qbds1.joinMode(JoinMode::InnerJoin);
   //Qbds1.relations(true);
 
     
   sysTableLookup.parmQuery(query);
   sysTableLookup.addLookupfield(fieldNum(VendTable, AccountNum),true); 
   sysTableLookup.addLookupfield(fieldNum(VendTable, party));
   sysTableLookup.performFormLookup();