CKEDITOR.plugins.add('footnote',
{
    init: function(editor)
    {
        var pluginName = 'footnote';
        CKEDITOR.dialog.add(pluginName, this.path + 'dialogs/footnote.js');
        editor.addCommand(pluginName, new CKEDITOR.dialogCommand(pluginName));
        editor.ui.addButton('Footnote1',
            {
                label: 'Footnote or Citation',
                command: pluginName
            });
    }
});