[flexcoders] add event listener to line chart label

[Jason Rayles]

I want to add a listener to the labels in my line chart. How do I go 
about that?

I thought that I could access the labels with labelElements, but when I 
do linechart1.labelElements, I get the following error:
Attempted access of inaccessible property labelElements through a 
reference with static type mx.charts.LineChart.

Thanks,
Jason