sorry guys if it did not work for you. I will have to get back to you guys at a later date after I get a chance to look at it. But the screen shots are from actually running the report, so I know it works.
But glad to see at least one person who could make use of this trick.
As I mentioned in the article, SSRS 2005 really has lots of limitation but it is not that there are no workarounds. You cannot actually halt the report processing, because this validation occurs after you run the report. So here is what you can do...
When user clicks No or Cancel, the give code returns a boolean "False". So based on this value, you can display a message in the report body, inside a textbox or label, asking users to enter the parameters again or whatever message you want.
You will actually be altering the visible/Hidden property of your entire table or matrix or whatever controls you have in your report to hide when that parameter value is false and in that case you will show your textbox or label with message and hide this message when True.
This should solve your problem. Let me know if this was not clear.
always Happy, always Prasanna :-)