URL for the child report

Today i have learnt how to run the report using the URL. We can actually pass the parameter to the reports using the URL. I created simple parent and child reports. Passed the reports selected in Parent report to child report.
THE URL WILL look like this:

--crn/cgi-bin/cognos.cgi? b_action = xts.run&m = portal/report-viewer.xts&method = execute &m_obj = /content/package [@name = package name] /folder[@name = folder_name]/report[@name = report_name] &outputFormat =PDF

You can pass single-select, multi-select and multi parameters from parent to child report.