title: How to get index of a point in Highcharts?
body: <p>I'm using "Time data with irregular intervals" chart of Highcharts. As you know when mouse moves over points of line the formatter function runs and shows some information. I want to know index of the point that mouse moves over it. So if mouse moves over first point of the line, tooltip shows "1" and the second point shows "2" and so on. thnx.</p>