Greetings!

I have a question on how to pass multiple variable in ajax. I'm making a pagination in ajax. I just downloaded the code.

Code:
script>
window.onload = function() {
SANAjax('Listing','1');
};
////////////////////// AJAX
 
var HttPRequest = false;
 
	   function SANAjax(Mode,Page) {
 
		  HttPRequest = false;
		  if (window.XMLHttpRequest) { // Mozilla, Safari,...
			 HttPRequest = new XMLHttpRequest();
			 if (HttPRequest.overrideMimeType) {
				HttPRequest.overrideMimeType('text/html');
			 }
		  } else if (window.ActiveXObject) { // IE
			 try {
				HttPRequest = new ActiveXObject("Msxml2.XMLHTTP");
			 } catch (e) {
				try {
				   HttPRequest = new ActiveXObject("Microsoft.XMLHTTP");
				} catch (e) {}
			 }
		  } 
 
		  if (!HttPRequest) {
			 alert('Cannot create XMLHTTP instance');
			 return false;
		  }
 
		
			var pmeters = 'mode='+Mode+'&Page='+Page;
				var url = 'SANajax.php?'+pmeters;
			HttPRequest.open('POST',url,true);
 
			HttPRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
			HttPRequest.setRequestHeader("Content-length", pmeters.length);
			HttPRequest.setRequestHeader("Connection", "close");
			HttPRequest.send(pmeters);
 
 
			HttPRequest.onreadystatechange = function()
			{
 
			if(HttPRequest.readyState == 3)  // Loading Request
				  {
	document.getElementById("listingAJAX").innerHTML = '<img src="loader.gif" align="center" />';
				  }
 
				 if(HttPRequest.readyState == 4) // Return Request
				  {
		var response = HttPRequest.responseText;
 
 
				   document.getElementById("listingAJAX").innerHTML = response;
				  }
 
			}
 
 
			   }</script>
<p>

<div id="listingAJAX"></div>
</p>
<?php 
$avail = $_POST['avail']; 
$sec = $_POST['section']; 

?>
<input type ='hidden' name = 'avail' value = <?php echo $avail;?> >
<input type ='hidden' name = 'sec' value = <?php echo $sec;?> >

</body>
</html>
my problem is how to send the hidden value in my page.
thank you.