apply layer style

There is a plug-in called "ScriptingListener.plugin" (It should be found in the "Scripting Guide/Utilities" directory of your Photoshop application folder) If you place this in your Plug-Ins folder, Photoshop will write 'ScriptListener' Javascript code for every action you do in Photoshop (a text file with this code will appear on your desktop). This is a way to script parts of the application that are not otherwise exposed with Javascript commands.

Note - it's not exactly the Javascript that you would normally write, it can take a little getting used to to figure out what the steps it writes mean, but you can often determine what each variable it uses is for. You usually wouldn't use this for programming things that can be done with the Javascript commands available, only when there is no command to perform the task you need.

You'll probably want to remove the plug-in for normal use, and only reinstall it to record the steps that you need. Since it continuously writes to the text file for everything you do in Photoshop, finding the steps you want can be difficult if you have been 'recording' for a while. Plus, many have claimed that it slows Photoshop down as it is writing the text for each action you do. Personally, I only install mine when I need it, mostly for the first reason.