function processZipCodeSelection(req) {
var cityAndState = req.responseText.split(',');
setCityAndStateFields(cityAndState[0], cityAndState[1]);
Fat.fade_element("form:city");
Fat.fade_element("form:state");
}
It places the city and state in their proper fields and provides a visual cue
that the fields have changed by slowly fading the background color.
This is accomplished with the Fade Anything Technique library:
<script type="text/javascript" src="fat.js"></script>