Obtain attribute values from a MapService layer to use in custom widget

I have a custom widget that I am running in the Flex Viewer version 3.2 (uncompiled). The custom widget takes user inputs for a geoprocessing service, passes them to the server, and renders the results. I am working on some new functionality and would like the user to be able to click on one or more points from a MapService layer and build up a list of PointIDs. This list would then be entered as an input string in my custom widget.

I have looked at some of the Flex API samples like http://resources.arcgis.com/en/help/...000000r000000/ but am stuck on:

• using this code within my custom widget, as opposed to within a standalone map
• whether to make a graphics layer from the map service layer or query the map service layer
• selecting multiple points (e.g. control-click)

If anyone has suggestions or good examples, I'd appreciate it.

Thanks,
-Erik