<script type="text/javascript">
$(document).ready(function()
{
$('#dynamic').calendar(
{
adapter: 'adapter.php',
onSelectDate: function(date, month, year)
{
if (this.isAvailable(date, month, year)) {
document.getElementById("date").value = date;
document.getElementById("month").value = month;
document.getElementById("year").value = year;
document.getElementById('test').submit();
}
},
});
<form id="test" name="test" method="post" action="book_slot.php">
<input type="hidden" name="date" id="date" value="">
<input type="hidden" name="month" id="month" value="">
<input type="hidden" name="year" id="year" value="">
</form>