<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.10.0.js'></script>
<script type='text/javascript'>
$(function () {
$('.ba').on('change', function () {
var checked = $(this).prop('checked');
$('.tex').prop('disabled', !checked);
});
});
</script>
</head>
<body>
<input type="checkbox" class="ba" checked="checked" />
<input type="text" class="tex" />
</body>
</html>