My first mistake was not understanding the original poster's question - even after a few tries. My second mistake was replying whilst damn well knowing I cannot code very well yet.

I don't think those are really mistakes in this forum. This community should be a (mostly) judgement-free zone, and mistakes are allowed, and should be encouraged. That's how we learn. (Imagine if all posts had to be peer-reviewed by 3 saints?)

On the other hand, "I don't know" is an OK response (though you might catch some flack for it). "I don't understand ..." is better.

"I'm not sure, but try this..." is excellent, IMO. It shows you've put some effort into a response, and you'd like to know how it measures up. That response turns an ordinary question into The Quiz of The Day, stimulating others to join in the fray.

So don't be afraid to respond.