compare two tables & pick values

[#1]

hi experts,

     i have a table with selective partno, description, date for a particular sales with specific dates.

     i have another table with all partnos(not selective), different dates for return of sales.

     Now, the return of sales table should compare with the previous sales table & display the partnos of return which are available in       

     sales table alone. how can i do this.

    pls help me out in this regard as soon as possible

[giakoum]

add where exists in the Credit table.

and caution, you are naming pno in lowercase in Credit table. pno and PNO are considered 2 different fields in QlikView. they should be both upper or lowercase