OpenDocument Link not working as expected

I am using OpenDocument to open a crystal reports with two optional hierarchical parameters like below:

http://<server>:<>/OpenDocument/opendoc/openDocument.jsp?iDocID=<CUID>&sIDType=CUID&lsMparentPrompt=[<parent>]&lsMchildPrompt=no_value

My requirement is to open report by supplying one parameter only and skipping the other. The problem I am facing is, above url is generating empty report instead of generating report only for given parent with all its childs. Is there anything, I am doing wrong here?

Any alternative solution to my problem is most welcome. Thanks in advance.