In general, it has been my experience that DW leaves any non-DW JS alone.
However, it provides no interface for editing the script except by editing
the code in the code view. When you select an object to which a non-DW
script has been attached, the Behaviors palette will show something like
"Custom Script: myScript ()" if "myScript" is the name of the non-DW script.
You can delete the script from this palette, but that's all you can do via
-- James M. Shook