Fire onchange event for single option in Select

[Optimaximal]

Maybe I've missed or misunderstood the documentation, but is there anyway to trigger the onChange event for just a single option in a instance?

i.e. there are 4 options available, but I need to trigger an onChange event to change the CSS to display a form field (or insert it from scratch using JS) when (for example) the second value is selected and then remove it if it's not selected?

I suppose removing it when any other field is selected would require usage of the onChange event looking at the option value? Any ideas?

[lavira]

you can use the onChange on the select element for this