How does javaScript select an existing layer mask in order to make an alpha channel from the selection?

Hello javaScripters,

I have hundreds of PSD files that need all existing layer masks made into alpha channels. The PSDs have either a floating base layer or a locked background layer with no mask and 1 - 16 additional layers with corresponding masks. If I manually make a mask into an alpha channel, I select the layer with the mask, This makes the layer active so when I switch to the Channels panel, it appears directly under the blue channel. Then all i have to do is right click over the mask and choose Duplicate Channel. It's pretty easy to do, however, I would like to automate this using JS. When I initially attempted to do this with code, the JS doesn't see this mask in the Channels panel - it only sees the red, green and blue, so duplicating doesn't work. The other way to do this manually is to make a selection of the mask for the active layer by pressing "Cntrl + clicking" and then copy / paste it into a new blank alpha channel. This seems like it would work, but I don't know how to write the code to make the selection of the active layer mask. Does anyone know how to do this? Is there a completely different way to do this? I'm open to suggestions!

Below is the code that I have so far. It has a lot of comments to explain what's going on. I also included some alerts which helps me figure out how far along the code executes for trouble shooting purposes.

#target photoshop

// global variables

var openDocs = app.documents;

var docCount = openDocs.length;

var docActive = app.activeDocument;

var  docLayers = docActive.artLayers;

var docLayer = docActive.artLayer;

var docActiveLayer = docActive.activeLayer;

var layersCount = docLayers.length;

var docChannels = docActive.channels;

var docActiveChannel = docActive.activeChannel;

var x=docLayers.length -1;  // iteration default value for do - while loop

var y = 3;                          // iteration value for mask in channels panel - skips past red, green & blue

if (docLayers.length < 2) {     // checks to see if there are at least 2 layers in the document

alert("There needs to be at least 2 layers in this document");   

    } else {

do {

    docActiveLayer = docLayers;

    alert("The active layer is " + docLayers.name);

        if (docLayers != docLayers[(docLayers.length - 1)] ) {      // checks to see if active layer is the background or base layer. If so, it skips it

            docChannels.add();                                            // make a new blank alpha channel

            var channName = docActiveLayer.name;              //  active layer name is assigned to variable

            docChannels[(y+1)].name = channName;           // alpha channel name is changed to match the active layer name

                                                                             <--------//  code to make selection of mask should go here

            y+=1;

            }  // end if active layer is background or base layer

    x-=1;

    alert("The active layer is " + docActiveLayer.name + " and x = " + x );

    } while (x > 1 );

}  // end if doc has less than 2 layers