add parameters to button's POST request

[iwuser]

>>I think I need to be able to add this parameter on the URL 
>>generated by the button click - that should do the trick.


You could also use cookies to store your params like so

Ok, thanks, I haven't thought of that. But now that I've tried, it didn't work: when I'm setting it, there's no roundtrip to the browser, so it's never set and then on the button click, the server starts a new session and there's no such cookie there at that point.

Do I need to somehow force the cookie to be sent to the caller? - all this is happening in OnCreate event of the main form, if that's important.