consider the link http://jsfiddle.net/5D5eD/24/. In this example if there is one more field in data array like
[2,2,"a"],
[3,3,"b"],
[4,4,"c"],
[5, 4,"d"],
[5.5, 5,"e"],
[6, 6,"f"],
.
.
.
a,b,c, is a character string, what code should add to the program so as to obtain the character string on mouse-hovering at respective datapoints on chart, that is on hovering the mouse near [2,2] it should show a and near [3,3] it should show b..... so on. How to do this ?