Making the points always visible in a flex line chart

I'm trying to do something very similar to this example (source code enabled):

http://www.sunild.com/proto/line_chart_example.html

When you hover over each data point, a circle appears i开发者_运维百科ndicating that this is a point. How do I keep those circles visible at all times?

Edit: this example isn't mine, but you can view the source enabled here:

http://www.sunild.com/proto/line_chart_example_src/index.html

Umm, the case you show is a working example giving no details about the code itself. There are enormous ways the code could be. For Eg - The code could be keeping an event listener over & out a mouse event...So removing it pretty much keeps the circles there. But still I suggest show at least what you are doing, if not that code to get some clue.