This file shows how to create a hint that apppears to use an alert as its host.
The problem
A construct xf:alert/xf:hint is not permitted in XForms, the only xforms element that is explicitly premitted beneath alert, label, or hint, is output.
The Cure
Use output with a hint inside the alert. - view source to see how:
The input is invalid if its value is not "hello"
I am labelhello sailor
Or an image - Note, this does not work on the filesystem in Vista+IE7, but will work from both HTTP and HTTPS. I'm not sure about other environments, I suspect it has something to do with IE7/Vista security settings.
I am labelhello sailor
Look at this combo: