How to put dynamic content in YUI gallery-tooltip for bootstrap

How to put dynamic content in YUI gallery-tooltip for bootstrap

bootstrap-tooltip" from
http://jshirley.github.com/bootstrap/javascript.html#tooltips and I want
to dynamically put content when someone enters some incorrect input in the
input field.
This is how I am trying it:
<script>
var v=new Y.Bootstrap.Tooltip({ selector :
'*[rel=tooltip]',trigger:'focus',placement:'right' }).render();
</script>
My html part:
<input type="text" class="form-control" placeholder="First Name"
required="" id="firstNameId" rel="tooltip"/>
Now how can I put the content in the tooltip dynamically.