object_annotation = {
                        from: index,
                        to: index+1,
                        id: array_elem[0],
                        label: {
                          text : '+',
                          style: {
                            color: 'black'
                            }
                        },
                        events:{
                            click: function(e, index)
                            {
                                return function()
                                {
                                    console.log(index);
                                }(e, index);
                            }
                        },
                        color: color
                    };