as you can see at http://www.flotcharts.org/flot/examples/interacting/index.html
(hover your mouse on the graph and look at bottom: show mouse position)
you can have mouse coordinates on the graph,

today in highcharts i can only have the mouse coordinates on points,

but i want to have a feature that can allow to get the coordinates of the mouse independently of the drawed points.

it would be great!