procedure Page1OnBeforePrint(Sender: TfrxComponent);
begin
MasterData2.RowCount:=<MyRowCount>;
end;
procedure TfrmMain.Button1Click(Sender: TObject);
begin
// (FindComponent('MasterData2') as tfrxmasterdata).RowCount:=150;
frxReport1.Variables.Variables['MyRowCount']:=80;
frxReport1.ShowReport();
end;