kendo ui checkbox external data source doesn't work

I am using checkbox widget of Kendo UI:

<input type="checkbox" data-bind="checked: isChecked" />
<script>
var viewModel = kendo.observable({
isChecked: false
});

kendo.bind($("input"), viewModel);
</script>

The first thing is doesn't work. If I change the value of isChecked by true in the script, the HTML page doesn't show the checkbox checked.

The second thing is that I am using the data from a database, so, I need indicate to checkbox when this checkbox is checked. How can I do this ?

I don't have found this information in the telerik.com or Google or Stackoverflow :-((((

Can you help me?

Thanks in advance.

Wopper