For line chart : optional callback when events(click|mouseenter|mouseleave) on dot points.

callbackDotPoint: { // Allow you to defined callback on dotPoint events.
    'mouseenter': function(data){  },
    'mouseleave': function(data){  },
    'click': function(data){  }
},
pointDotCursor: 'pointer' // The CSS value for the cursor when dotPoint:hover

The callback receive the argument below :
{
    x, y // position of the dotPoint in the canvas
    bodyX, bodyY // position of the dotPoint in the page
    x_value // The value of the point
    z_value // An extra value you can set to the point
    id_dataset // A unique ID to describe the dataset
}

Please check the demo page to understand easier.

I tried the code with Chrome and firefox. It must be compatible with all the browsers including old IE. I need you to try !