Custom lookup

public void lookup(FormControl _formControl, str _filterStr)

{

sysTableLookup sysTableLookup;

Query query = New Query();

QueryBuildDataSource qbdsJour, qbdsTrans,qdbsVend;

QueryBuildRange qbr;

;

sysTableLookup = SysTableLookup::newParameters(tableNum(VendPackingSlipJour), _formControl);

qbdsJour = query.addDataSource(tableNum(VendPackingSlipJour));

qbdsTrans = qbdsJour.addDataSource(tableNum(VendPackingSlipTrans));

qbdsJour.relations(true);

qbr = qbdsTrans.addRange(fieldNum(VendPackingSlipTrans, ItemId));

qbr.value(<ItemId>);

qbdsTrans.relations(true);

sysTableLookup.addLookupfield(fieldNum(VendPackingSlipJour, GRNNumber_IN));

sysTableLookup.addLookupfield(fieldNum(VendPackingSlipJour, PurchId));

sysTableLookup.addLookupfield(fieldNum(VendPackingSlipJour, OrderAccount));

sysTableLookup.parmQuery(query);

sysTableLookup.performFormLookup();

}