Fetch records count using PHP and MongoDB - mongodb

Question

I have an HTML page with a department selectbox. when end user selects any department I have no show him the no of employs in that department. The employee collect
<select multiple="" class="chosen-select choice" id="form-field-select-4" data-placeholder="Choose a Department..." onchange="show_employee_count(this.value)">
<option value="Management">Senior Management</option>
<option value="Legal">Legal</option>
<option value="Operations">Operations</option>
<option value="Administration">Administration</option>
<option value="R&D">R&D</option>
<option value="Sales & Marketing">Sales & Marketing</option>
<option value="Finance">Finance</option>
<option value="Technology">Technology</option>
<option value="Customer Service">Customer Service</option>
<option value="Pro Services">Pro Services</option>
<option value="HR">HR</option>
</select>
The count of employee to show in this container div
<div id="emp_count"></div>

Answer 1

I have tried this as :
HTML
<select name='department' id='department'>
<option value="Management">Senior Management</option>
<option value="Legal">Legal</option>
<option value="Operations">Operations</option>
<option value="Administration">Administration</option>
<option value="R&D">R&D</option>
<option value="Sales & Marketing">Sales & Marketing</option>
<option value="Finance">Finance</option>
<option value="Technology">Technology</option>
<option value="Customer Service">Customer Service</option>
<option value="Pro Services">Pro Services</option>
<option value="HR">HR</option>
</select>
<div id="leads_coount"></div>
JS Code
<script type="text/javascript">
$(function(){
$("#department").change(function(){
var selectedDepartment = $(this).find(":selected").val();
console.log("the department you selected: " + selectedDepartment);
$.ajax({
type: "POST",
url: "ajax.php",
cache: false,
data: { method: "get_lead_count", department: selectedDepartment }
})
.done(function( leads ) {
$( "#leads_coount" ).html(leads);
}).fail(function( jqXHR, textStatus ) {
alert( "Request failed: " + textStatus );
});
});
});
</script>
ajax.php
<?php require_once('DataAccessBean.class.php');
if($_POST['method'] == 'get_lead_count') {
// select a collection
$collection = new MongoCollection($db, 'employs');
// find the collections with department
$clause = array('Department' => $_POST['department']);
$cursor = $collection->find($clause)->count();
echo 'There are '.$cursor.' employees available in this department';
//echo $_POST['department'];
}
Is there a better way to do?