How to passing a report parameter to another report

Hi, 

I have a sales report and that report have 2 parameters (start date and end
date)

so If user want to view a sales report from 1 april 2006 to 31 may 2006, he will
enter :
4/1/2006 in start date text box
5/31/2006 in the end date text box


I need to build a report that have a drill down capability, so if user want to
see a detailed report - for example he want to see all sales detail for
"chocolate chips" he just need to click on chocolate link and a new
report will show up. My problem is : 

I don't know how to pass "start date" and "end date"
parameter to another report (detailed report).