The trick is to get readers to the point where they think to themselves:
"I can answer this"
The longer the question is, and the more complex the question is, the more likely people will just look at it and decide that they'd rather look for something else that's easier to answer.
Your question, although not a bad question, at least for me, didn't get the reader to the "I can answer this" stage very fast.
I think part of the reason for this is that your actual problem: "it doesn't work with Chrome" was below the fold, where people won't initially see it, and it wasn't exactly clear what "Doesn't work" meant.
Did It mean that the user can select multiple items? Is your onchange event even firing. do you have errors in your error console? etc.
To entice people to answer you question you want to:
- Simply and clearly define your requirements and problem.
- If your code is long or sensitive, include a SSCCE - Small Self-Contained Complete Example.
- Always explain how "It doesn't work".
- Include relevant information and code. Exclude irrelevant code(unless asked for)
In general, the more work it takes to get the reader to the point where they believe they can answer the question, the less likely that they'll do that work.