return select box and checkbox through ajax

I want to show select boxes and check boxes(as checked), from an AJAX response. I am passing a string and then exploding to get array results for select boxes. How can I do this with checkboxes too.

in escalation_ajax,

echo '<option value="'.$id.'">'.$reporting_head.'</option>'.",".'<option value="'.$des_id.'">'.$des_name.'</option>'.",".'<option value="'.$designation_email.'">'.$rep_head.'</option>' ;

and escalation.php

 <b>CC To:</b><br>
     <?php 

           $sqlrep = mysql_query("SELECT id, reporting_head FROM tbl where level > 0  GROUP BY reporting_head");
                  while ($rows1 = mysql_fetch_assoc($sqlrep)){   
                          $rep_id2    = $rows1['id']; 
                     $repname2    = $rows1['reporting_head'] ;

             echo "<input type='checkbox' name='cc2' value='".$rep_id2."'> ". $repname2 ."<br>";
         }

?>

<script type="text/javascript">
$(document).ready(function()
{  

$("#desig").change(function()
{
var designationname2 = $(this).find("option:selected").text()
var id=$(this).val();
var dataString = { 'id': id , 'designationname2': designationname2};

$.ajax
({
type: "POST",
url: "escalation_ajax.php",
data: dataString,
cache: false,
success: function(html)
{

var data = html.split(",");
$("#rephead").html("");
$('#rephead').append(data[0]);
$("#rephead1").html("");
$('#rephead1').append(data[0]);
$("#rephead2").html("");
$('#rephead2').append(data[0]);
$('#dd').html("");
$('#dd').append(data[1]);
$('#rephead3').html("");
$('#rephead3').append(data[2]);

}
});
});
});
</script>