Morris graphs. Have custom tooltip when hover

http://jsbin.com/finuqazofe/1/edit?html,js,output

{ y: ..., x: ..., label: "my own label"},'

...
Morris.Line({
    hoverCallback: function(index, options, content) {
        var data = options.data[index];
        $(".morris-hover").html('<div>Custom label: ' + data.label + '</div>');
    },
    ...
    other params
});

Piece of cake. Demo and code:

<script type="text/javascript">
Morris.Bar({
    element: 'bar-example',
    data: [
        {y: '2006',a: 100,b: 90}, 
        {y: '2007',a: 75,b: 65}, 
        {y: '2008',a: 50,b: 40}, 
        {y: '2009',a: 75,b: 65}, 
        {y: '2010',a: 50,b: 40}, 
        {y: '2011',a: 75,b: 65}, 
        {y: '2012',a: 100,b: 90}
    ],
    hoverCallback: function(index, options, content, row) {
        return(content);
    },
    xkey: 'y',
    ykeys: ['a', 'b'],
    stacked: true,
    labels: ['Series A', 'Series B'] // rename it for the 'onhover' caption change
});
</script>

ARGUMENTS:

1: index: it represents record number i.e. from 0 to n records.

2: content: this is default hover div.

3: option : you data is inside this, before return(content);. do console.log(options) to view details.

4: row : to see the use of row below is an example.

hoverCallback: function (index, options, content, row) {
                     console.log(row);
                     var hover = "<div class='morris-hover-row-label'>"+row.period+"</div><div class='morris-hover-point' style='color: #A4ADD3'><p color:black>"+row.park1+"</p></div>";
                      return hover;
                    },

UPD:

For flying label, you need to add Morris CSS stylesheet to the code - demo

IMPORTANT NOTE

Flying labels works since version 0.4.3