Get horizontal axis label when point on a line chart is clicked

[Peter Haworth]

I have a line chart with dates along the horizontal axes.  When the user clicks on a pint on the line, I need to get the date in horizontal label to pass to a report produced from the chart.

I use getSelection() to get the info on what was clicked but it returns only a row and column number with no obvious means to use it to get the label.

Any ideas?