How to add a user defined css class name for chart surface text?

Hi,



how to add a userdefined css class name for chart surface text?





I have to add my css class in below code? can any one give me idea?



var sprite = chart.surface.add({

type: 'text',

id: me.toolId + '_donutLabel',

text: surfaceText,

font: '30px Arial bold red',

x: me.textXAxis,

y: me.textYAxis

});