Display empty rows

I am creating some reports with crystal reports 8.5

I made crosstabs listing the sales of certain products by store and month.

The stores are listed in the rows, products and months are in the columns. In the complete yearly reports everything is fine, because there are no empty rows.

When i create subreports for just a certain month or product, there might be empty rows, like, there might have been no sales of that particular product, in that store in that month. Instead of just displaying a row with the store name and Zero value, it just doesn`t show the row at all.

I need those empty rows to show and display zero values. The option "suppress empty rows" is not checked.

Any ideas ?

Example
...............January 2007
...............Product 1
Store1......0 <- this row is not displayed
Store2......6
Store3......24You'll need an outer join somewhere, rather than an inner join - read the help on join types, or describe your current tables and joins.|||I am just beginning in crystal but I did have the same issue but my training yesterday was about table joints.
You have to have your primary table as your "source" table where you have most of your data. When you link your secondary table, go to link options and you need to have the linking as "left join or outter join ...not Equal". Even though you have no value on that one record, it will show it with an empty cell or box but you will see everything else from that record. I still wouldn't know how to display the zero.