Make a if loop according to what returns the ajax html(data) - ajax

Question

I want to make a if loop according to what returns html(data), so how can I get in my ajax script a var returned by "form_treatment.php" ? I want to close the colorbox (a lightbox) containing myForm only if "form_treatment.php" returns a var PHP with a "true" value.
$('#myForm').submit(function() {
var myForm = $(this);
$.ajax({
type: 'POST',
url: 'form_treatment.php',
data: myForm.serialize(),
success: function (data) {
$('#message').html(data);
// Make a if loop according to what returns html(data)
}
});
return false;
});
form.php :
<form method="post" action="form_treatment.php" >
<input type="text" name="user_name" value="Your name..." />
<button type="submit" >OK</button>
</form>
form_treatment.php :
if ( empty($_POST['user_name']) ){
$a = false;
$b = "Name already used.";
} else {
$already_existing = verify_existence( $_POST['user_name'] );
// verification in the DB, return true or false
if( $already_existing ){
$a = false;
$b = "Name already used.";
} else {
$a = true;
$b = "Verification is OK";
}
}

Answer 1

Try adding dataType : 'json' inside your $.ajax() call, and then, in your php file, respond with nothing but a json object such as:
{ "success" : true, "msg" : 'Verification is OK' }
Then, inside your $.json() success function, you can access anything from the server's response like so:
if (data.success) {
alert(data.msg);
}
I know you said you want to loop, but that's just an example. Note that PHP has a great little function called json_encode() that can turn an array into a json object that your JavaScript will pick up just fine.

Answer 2

$('#myForm').submit(function() {
var myForm = $(this);
$.ajax({
type: 'POST',
url: 'form_treatment.php',
data: myForm.serialize(),
success: function (data) {
// if data is a variable like '$a="Verification is OK"':
eval(data);
if ($a == 'Verification is OK')
$("#colorBox").close() // or whatever the close method is for your plugin
else
$('#message').html($a);
}
});
return false;
});

Answer 3

The var "data" is the response being passed back from your PHP file. Therefore, you can do something like:
...success: function (data) {
if (data == 'Verification is OK') {
// Make a if loop according to what returns html(data)
}
}

Answer 4

You just have to make a simple comparison in your success function in the ajax request, like this:
success: function (data) {
$('#message').html(data);
if(data == 'Verification is OK')
{
// make the lightbox show
}
}