It works fine in Safari (haven't tested IE yet) but in Firefox, clicking on the link prompts it to display a blank page with the word "true". The function executes OK on the main page, but can anyone tell me why FF does this? And if I can stop it? I've tried adding the statement target="_self" to the link attributes, but it makes no difference.
Thanks also for the "link-to-non-JS-support_page.html" suggestion. I assume then that onclick takes precedence over href?
Another quirk of this script is that if I use a CSS class to style the <div> that's expanded/collapsed, then initially it's necessary to click twice on the link to get the toggle to take effect. If I use an inline style declaration, the first click initiates the function so there's no need to click again. Do you know why using CSS should require a second click?