<script type="text/javascript">

$().ready(function() {

	function startChange() {
		var startDate = start.value();

		if (startDate) {
			startDate = new Date(startDate);
			startDate.setDate(startDate.getDate() + 1);
			end.min(startDate);
		}
	}

	function endChange() {
		var endDate = end.value();

		if (endDate) {
			endDate = new Date(endDate);
			endDate.setDate(endDate.getDate() - 1);
			start.max(endDate);
		}
	}

	var start = $("#valid_from").width(200).kendoDatePicker({
		change: startChange,
		format: "dd-MM-yyyy"
	}).data("kendoDatePicker");

	var end = $("#valid_to").width(200).kendoDatePicker({
		change: endChange,
		format: "dd-MM-yyyy"
	}).data("kendoDatePicker");

	start.max(end.value());
	end.min(start.value());		
});

</script>

<form action="xxx" method="post">
<input type="hidden" name="request_id" value="9" />
<input type="hidden" name="product_id" value="19" />
<table>
<tr>
	<td><strong>Valid From</strong></td>
	<td> : 
		<input type="text" name="valid_from" value="21-02-2012" id="valid_from" readonly="readonly" maxlength="20" size="20"  />
	</td>
	<td><strong>Valid To</strong></td>
	<td> : 
		<input type="text" name="valid_to" value="21-02-2012" id="valid_to" readonly="readonly" maxlength="20" size="20"  />
	</td>

</tr>
<tr>
	<td colspan="3">
		<input type="submit" name="btnSave" value="Save"  />
		<input type="button" id="btnBack" value="Back" onclick="window.history.back()" />

	</td>
</tr>
</table>
</form>

array(6) {
  ["request_id"]=>
  string(1) "9"
  ["product_id"]=>
  string(2) "19"
  ["btnSave"]=>
  string(4) "Save"
}

Javascript Dependencies for Grid. Item 15. kendo.pageable.js (if paging is enabled) substitute on kendo.pager.js

http://www.kendoui.com/documentation/javascript-dependencies.aspx