In amCharts flash chart there is a event name clickGraphItem which work as click on graph item and after fetching this event we can do any action on graph item click.
You can add event handlers to the AMCharts Javascript library in the following way
// add click listener chart.addListener("clickGraphItem", handleClick);
Here is jsFiddle for this:
http://jsfiddle.net/amcharts2/cV8GG/