trying to get velocity for both axis.

gistfile1.js

    var btnPressed;
    var distance = [ 0, 0 ];
    var coords = [ 0, 0 ];

    var trackMovment =  function( evt ) {

        distance[0] += Math.abs( evt.pageX - coords[ 0 ] );
        distance[1] += Math.abs( evt.pageY - coords[ 1 ] );

        coords[0] = evt.pageX;
        coords[1] = evt.pageY;
    };

    document.body.addEventListener('mousedown', function( evt ) {

        distance = [ 0, 0 ];
        coords = [ 0, 0 ];

        btnPressed = new Date().getTime();

        document.body.addEventListener('mousemove', trackMovment );

    });

    document.body.addEventListener('mouseup', function( evt ) {

        document.body.removeEventListener('mousemove', trackMovment );

        var elapsed = new Date().getTime() - btnPressed;
        var velocity = [  distance[0]/elapsed, distance[1] / elapsed ];
        
        window.external.notify( velocity[0] + ' ' + velocity[1] );
    });