width: 300px;
height: 100px;
var heartbeat1 = new zeu.Heartbeat(document.getElementById('heartbeat-1'));
setInterval(function() {
heartbeat1.beat();
}, 1000);
var heartbeat2 = new zeu.Heartbeat(
document.getElementById('heartbeat-2'), {
lineColor: 'red',
fontColor: 'grey'
});
heartbeat2.lineColor = 'blue';
heartbeat2.fontColor = 'green';
setInterval(function() {
heartbeat2.beat();
}, 1500);