Cognos Reports - No Prompt Page

Cognos Reports - No Prompt Page

I am new to Cognos reports, so bear with me.
I have a report that has two parameters (call them x and y). I have a
prompt page for x and y. The user can supply those values and click finish
to be taken to the report. I am looking for a way to only show that prompt
page if those parameters are not passed in the url string. If those
parameters are set, I want to go directly to the report. I have tried some
js to automatically act as though the finish button has been called, but I
am just getting cognos errors. Any suggestions as to how I can accomplish
this? The prompt page is having the prompt controls set to the values for
x and y in the url.
js -
<script type="text/javascript">
promptAction('finish');
</script>
cognos error -
The secondary request failed. The requested session does not exist and the
secondary request does not contain enough information to recreate the
session. Contact your Administrator.