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/*
  FUNCTION DESCRIPTION:
    Check wether the current layer has a mask or not
    
  INPUT:
    None
    
  OUTPUT:
    Returns true or false
    
  NOTE:
    None
*/

function hasLayerMask() {
	try {
		var ref = new ActionReference();
		var keyUserMaskEnabled = app.charIDToTypeID( 'UsrM' );
		ref.putProperty( app.charIDToTypeID( 'Prpr' ), keyUserMaskEnabled );
		ref.putEnumerated( app.charIDToTypeID( 'Lyr ' ), app.charIDToTypeID( 'Ordn' ), app.charIDToTypeID( 'Trgt' ) );
		var desc = executeActionGet( ref );
		if ( desc.hasKey( keyUserMaskEnabled ) ) {
			return true;
		} else {
			return false;
		}
	} catch(e) {
		return false;
	}
}