I've only just started playing with AJAX, as part of a project I'm dealing with at work.

The specific piece I'm stuck on at the moment is this:

I have a form with a lot of fields, two of which are subnet (a drop box populated from a database, via PHP) and IP address (a text input box). When the user selects a subnet, the value is sent to a PHP script that queries the DB and returns the next unused IP address. If all I wanted was to display that in a div next to the IP input box, I'd be set -- that works fine.

Unfortunately, I can't for the life of me figure out how to get the returned data into a text input box, which is what I actually want.

I know that document.getElementById("div_id").innerHTML=request.responseText; will display the text in a div in my sample code. I found a post somewhere that implied that frm.getElementById("input_id").value = request.responseText; would do the job for a text input, but it doesn't, at least in any of the browsers I've tested.

If anyone could point me in the right direction, I'd greatly appreciate it.

Thanks in advance,
Alex