Photoshop Scripting - Smartlayer stack mode mean

Hi,

I have a script that calculates the median of some images that are loaded automatically into PS. I want to change the median to mean, but I can't find any good documentation about PS scripting, does anyone know how to do that? Here's my code for calculating the median:

function makeMedian(){

var idapplyImageStackPluginRenderer = stringIDToTypeID( "applyImageStackPluginRenderer" );

var desc6 = new ActionDescriptor();

var idimageStackPlugin = stringIDToTypeID( "imageStackPlugin" );

var idmedn = charIDToTypeID( "medn" );

desc6.putClass( idimageStackPlugin, idmedn );

var idNm = charIDToTypeID( "Nm " );

desc6.putString( idNm, """Median""" );

executeAction( idapplyImageStackPluginRenderer, desc6, DialogModes.NO );

}

Thanks!