How to pass DSN to the sub - report

[Guest_imported]

I have a problem with invoking a crystall report.

I have crsyatll report which contains a sub report.

when i invoke this report thru crystall report designer
it asks for authentication twice.

When i invoke this report thru VisualBasic,it throws an
error "sql Server cannot open"
If i suppress the sub - repoprt ,it works fine without
any problem

(I am passing authentication to the report only once)

I was told that i have to pass authentication twice to the report as it has sub report.

if it so,how to pass authentication for the sub-report.

I don't know,how to pass authentication to the sub-report.

Thanx in advance
Rajan