conditional prompting in Report Studio

[cognos_developer]

Hi ,
1.I need to have a prompt page with two check with name of two Reports displayed.
2.when 1st check box is checked 1st Report output will be displayed and when 2nd check box is checked 2nd Report oupput will be displayed
3. But 2nd Report has one extra prompt.so,after checking the 2nd check box that prompt will be displayed in the same prompt page (this prompt is optional for 2nd Report).After selecting all the requried prompt values it will show the Report output.

Please suggest me how I can achieve this.
Thanks