ARTICLE ID ISSUES: Error mesage displays "Invalid articleid"

Please, I need your help ! After following the tutorial, I had a challenge with my article id. I actually want to use it to collect comments from my site only. So when I set the whole thing up, on trying to test my website for the comment, I get an error that says "Invalid article id". Latter, I went to the form and set articleid="1" instead of articleid="articleid" in the code, but the error still shows. Please help me with a better way of getting the article id of a page. Thanks