test mask visibility in pscc 2014

I have heard good comments about indesign scripting community.

It occurred to ask a Photoshop scripting question here given the good reputation of this community.

The photoshop document has a layer with a layer mask.

Using the extended script or javascript,

How would I test if the layer mask is visible or hidden?

Trying to create a script that toggles the visibility of a layer mask.

So far the script can call the showMask or hideMask functions independently.

The next step is to test for the mask visibility and call the corresponding function.

I believe this can be achieved with an if statement.

// if mask visible

     call hideMask()

// if mask not visible

     call showMask()

////////////////////////////////////////////////////////////////////

#target photoshop

//Make Photoshop the formost Application

app.bringToFront();

//Test for open document

if(app.documents.length > 0){

        //Select mask layer 255 fill

        var docRef = app.activeDocument;

        var layerRef=docRef.layers.getByName("255 fill");      //"Layer Name" 

        docRef.activeLayer=layerRef;

        // call showMask function

        //showMask ();

        // call hideMask function

        //hideMask ();

        //toggle mask visibility              

    }

else {

    alert("No documents are open");

    }

// FUNCTIONS

function showHideMask () {

    // showMask

    // =======================================================

    var idslct = charIDToTypeID( "slct" );

        var desc21 = new ActionDescriptor();

        var idnull = charIDToTypeID( "null" );

            var ref21 = new ActionReference();

            var idChnl = charIDToTypeID( "Chnl" );

            var idChnl = charIDToTypeID( "Chnl" );

            var idMsk = charIDToTypeID( "Msk " );

            ref21.putEnumerated( idChnl, idChnl, idMsk );

        desc21.putReference( idnull, ref21 );

        var idMkVs = charIDToTypeID( "MkVs" );

        desc21.putBoolean( idMkVs, true );

    executeAction( idslct, desc21, DialogModes.NO );

    }

function hideMask () {

    // hideMask

    // =======================================================

        var idslct = charIDToTypeID( "slct" );

            var desc22 = new ActionDescriptor();

            var idnull = charIDToTypeID( "null" );

                var ref22 = new ActionReference();

                var idChnl = charIDToTypeID( "Chnl" );

                var idChnl = charIDToTypeID( "Chnl" );

                var idRGB = charIDToTypeID( "RGB " );

                ref22.putEnumerated( idChnl, idChnl, idRGB );

            desc22.putReference( idnull, ref22 );

            var idMkVs = charIDToTypeID( "MkVs" );

            desc22.putBoolean( idMkVs, false );

        executeAction( idslct, desc22, DialogModes.NO );

    }