I have a couple places where user needs to select a name/place from a very long list. I have put the list in a portal which filters via relationship with whatever they key into a global field outside the portal.

Works pretty well, but you have to exit the field in order to see the filtered results in the portal.

Showed it to the user and he says "can you make it narrow down the list while I type?"

Lots of Windows dialogs in Windows apps do this so... it's expected.

So is there a way to do this? Is there some kind of looping script that might respond to each key stroke in the filter field?

I already have a plugin that can trigger a script upon exiting the field (I use EventScript from S4U). But is there one that can respond in real time as each letter is typed? ... or is there a native Filemaker way to do it?

There is no way to do it natively with Filemaker. If you start typing and hit tab that is the equvilent of clicking outside the portal.

If you really want or really need it to narrow down the list this technique is called "AutoFilter" I found a good template that shows AutoFilter below, Unfortunately it's not free, and it requires a plug-in, which is also not free.

http://www.nightwing.com.au/FileMaker/index.htm

Looks very cool but MenuMagic is a bit expensive. Thanks for the tip.