save image at gallery

what the issue at that code at android i want to save image at gallery

var img = $.photo_container.toImage().media;
 
            fileToShare = Titanium.Filesystem.getFile(Titanium.Filesystem.externalStorageDirectory, 'lactacyd_image' + moment() + '.jpg');
            fileToShare.write(img);
            Titanium.Media.saveToPhotoGallery(fileToShare.write(img),{
success: function(e) {
    Titanium.UI.createAlertDialog({
        title:'Photo Gallery',
        message:'Image Saved Successfully'
    }).show();      
},
error: function(e) {
    Titanium.UI.createAlertDialog({
        title:'Error saving',
        message:e.error
    }).show();