crystal report problem

I have these table CustomerMaster, Sales, Product_details

I made a crystal report from these tables …like

 this given below is my crystal report.........

CustomerCode       CustomerName     TotalSales     ProductName

11111001                    rahul                 230                  ProductName1

122220                        sam                  452                  productnName2

.

.

.

i have this ProductName field in my table ProductTable but i want to use this field value like a field in my Crystal report

 I want my report look like this given below..

CustomerCode       CustomerName     TotalSales     productName1   productName2   productName3………

11111001                    rahul                 230                 y                         y                          y

122220                        sam                  452                 y                          y                           y

.

.

Please help me….