This will work for you:
jsFiddle
<head>
<meta charset="utf-8" />
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css" />
<script>
$(document).ready(function() {
var date = new Date(), y = date.getFullYear(), m = date.getMonth();
var fSDate = new Date(y, m, 1);
var fEDate = new Date(y, m + 1, 0);
$.datepicker.setDefaults({
changeMonth: false,
changeYear: false,
showOtherMonths: false,
yearRange: '-0:+0',
dateFormat: 'yy-mm-dd',
defaultDate: +0,
numberOfMonths: 1,
minDate: fSDate,
maxDate: fEDate,
showAnim: 'fadeIn',
showButtonPanel: false
});
$('#date_start').datepicker();
}); //END document.ready()
</script>
</head>
<body>
<input type="text" id="date_start">
</body>
</html>