Help for web-based application - query

[SEO_guru]

Hi,
Is javascript 'onclick' popup help OK as a means to provide help for a web-based application? Or will it get blocked by popup blockers? I see that wordtracker uses this style of help - so does that mean its OK? Or would I be better off with macromedia's robohelp? Or any other recommendations? Before you answer, ideally I need to be able to dynamically control what gets displayed for my "what is?" help i.e. when users click on a "?" icon near one of the features, what it actually displays should depend on the context (value of a program variable - the application is written in PHP).

Thanks

[ADAM Web Design]

I've found that the popup blockers tend to allow popups if they're of this format:

This would be a help link

I'm guessing it's because it's an actual hyperlink, but I'm not 100% sure. I just know in the testing I've done, it works.

[speed]

If you use the code ADAMWebDesign gave you then any user without JavaScript enable will not be able to access the popped up page, which intern breaks WAI Priority 1 checkpoint 6.3 (http://www.w3.org/TR/WAI-WEBCONTENT/#tech-scripts)

Therefore you'll have to put the target page in the href and use the onclick handler, or have a scripted and noscript version of the link.