crystal reports problem

hi ,

in sales order item level each item contain sub items

(example:- system=keyboark,monitor,cpu

pen=refiel,cap,body)

like this each items contain sub items

i designed sub report for each item with their respective sub items in that

how to call that each sub report to main report depending on the sales order items

is it possible to call the subreport name as same as that of item to main report

pls give the solution for that

thanq