AJAX not being called when select box changed - php

Question

I am using jquery to call a PHP script when a select box changes. I am able to get the ID of the select item that changes, however I get no output from the PHP script. The Javascript is
function initagents() {
$('select.agent').on('change', function() {
var id = $(this).attr("id");
console.log(id);
var data = { id: id };
$.ajax({
type: "POST",
dataType: "json",
url: "updateagent.php",
data: data
}).done(function(msg) {
console.log(msg);
});
});
}
and the PHP is
print_r ( $_POST);
Any ideas?

Answer 1

Please use
echo json_encode($_POST['id']);
instead of
print_r($_POST);

Answer 2

You have made a mistake by placing the onChange event of the select box inside function initagents().
fixed code:
$('select.agent').on('change', function() {
var id = $(this).attr("id");
console.log(id);
var data = {
id: id
};
$.ajax({
type: "POST",
dataType: "json",
url: "updateagent.php",
data: data
}).done(function(msg) {
console.log(msg);
});
});

Answer 3

Just try with the following code:
function getID(val) {
alert(val);
$.ajax({
type: 'POST',
url: 'post.php',
data: {
id: val
},
success: function(data) {
alert(data);
}
});
}
<select name="pks" onchange='getID(this.value);'>
<option value="1">Option1</option>
<option value="2">Option2</option>
</select>

Answer 4

Seems your code is correct and it should send the data to php file. But also I see that, you are not sending selected value to php script. You are posting selected element ID.
Are you trying this in a sub folder ? make sure the php file path is correct in javascript. Better if you can try with the full path. For example
url: "http://localhost/myproject/updateagent.php",