focusout was added in v1.4. Three thoughts:
- Could you be using an earlier version of jQuery?
- Does your field really have the id
textbox?
- Are you also using Prototype or MooTools (or anything else that might be taking over
$)? If so, use jQuery's noConflict mode and use jQuery instead of $.
Other than that, it should (does) work.
Here's an example (using an alert as you did): http://jsfiddle.net/QzmZp/1/
and another not using an alert (because that freaked IE7 out): http://jsfiddle.net/QzmZp/2/
Someone earlier asked about browser versions, I've tried the above with Chrome 5, IE6, IE7, and FF3.6; all fine.
I did both an input and a textarea because I wasn't sure which you were using.