Trying to send data to mysql, receiving callback issue - php

Question

This is a mailing list script. It works by itself without jquery but I am trying to adapt it to work with ajax. However, without success. When the $.sql part is commented out it returns the variables in the url string successfully. However, when I uncomment that part of the js file and introduce the PHP into things it simply refreshes the page with the email address still in the input box. By itself, the PHP works so I'm at a loss as to where I'm going wrong. Here's what I have... any help would be appreciated.
Form :
<form name="email_list" action="" id="maillist_form">
<p><strong>Your Email Address:</strong><br/>
<input type="text" name="email" id="email" size="40">
<input type="hidden" name="sub" id="sub" value="sub">
<p><input type="submit" value="Submit Form" class="email_submit"></p>
</form>
JQuery :
$(function() {
$('#maillist_form').submit(function() {
var email = $("input#email").val();
if (name == "") {
$("input#email").focus();
return false;
}
var sub = $("input#sub").val();
if (name == "") {
$("input#sub").focus();
return false;
}
var dataString = $("#maillist_form").serialize();
//alert (dataString);return false;
$.ajax({
type: "POST",
url: "mailing_list_add2.php",
data: dataString,
success: function() {
$('#display_block')
.hide()
.fadeIn(2500, function() {
$('#display_block');
});
}
});
return false;
});
});
PHP :
<?php
// connects the database access information this file
include("mailing_list_include.php");
// the following code relates to mailing list signups only
if (($_POST) && ($_POST["sub"] == "sub")) {
if ($_POST["email"] == "") {
header("Location: mailing_list_add2.php");
exit;
} else {
// connect to database
doDB();
// filtering out anything that isn't an email address
if ( filter_var(($_POST["email"]), FILTER_VALIDATE_EMAIL) == TRUE) {
echo '';
} else {
echo 'Invalid Email Address';
exit;
}
// check that the email is in the database
emailChecker($_POST["email"]);
// get number of results and do action
if (mysqli_num_rows($check_res) < 1) {
// free result
mysqli_free_result($check_res);
// cleans all input variables at once
$email = mysqli_real_escape_string($mysqli, $_POST['email']);
// add record
$add_sql = "INSERT INTO subscribers (email) VALUES('$email')";
$add_res = mysqli_query($mysqli, $add_sql)
or die(mysqli_error($mysqli));
$display_block = "<p>Thanks for signing up!</p>";
// close connection to mysql
mysqli_close($mysqli);
} else {
// print failure message
$display_block = "You're email address - ".$_POST["email"]." - is already subscribed.";
}
}
}
?>
I won't put the include code in here because I'm assuming it is correct - unless the introduction of the jquery means this needs to be adapted as well.

Answer 1

Your AJAX is not catching back the result:
$.ajax({
type: "POST",
url: "mailing_list_add2.php",
data: dataString,
success: function(response) {
$('#display_block')
.hide()
.fadeIn(2500, function() {
$('#display_block').html(response); //just an example method.
//Are you sure the selector is the same?
//Can also be $(this).html(response);
}
});
And as noted by gdoron, there's no "name" variable. Maybe you meant "email" and "sub", respectively?
PHP response, also, isn't echoed back. Just put:
echo $display_block;

Answer 2

You don't echo an data from the server, not trying to get data in the success callback, and the fadeIn callback just have a selector,.
You check for the wrong variable:
var email = $("input#email").val();
if (name == "") { // Didn't you mean email?
$("input#email").focus();
return false;
}
var sub = $("input#sub").val();
if (name == "") { // Didn't you mean sub?
$("input#sub").focus();
return false;
}
How can it work!?