I am stuck with my portfolio PHP email.

There is a div containing email form. This div fades in (initially display: none; and than jQuery opens it) when the button "contact" is clicked. Validation for this form is done in PHP, so if all required data is typed in, PHP displays the sentence "Thank you for your email..."(instead of previously displayed form) and if all required data is not typed in, than the error message(s) is/are displayed beside the corresponding input tag(s).

The problem is that after clicking the submit email button, the popup which contains email form disappears and user cannot see the feedback (feedback will be there if user reopens the popup, but I doubt anyone would try to reopen the popup after it disappears - not intuitive).

I am trying to make that popup remain displayed with updated content ("Thank you for your email..." or eventual error messages), and I believe I should do that with jQuery AJAX but I do something wrong. Could anyone help me out with this please?

home.php:
PHP Code:
<?php
include 'includes/email.php';
?>
<!DOCTYPE html>
<html lang="en">
    <head>
        <title>myPortfolio</title>    
        <script>
            $('#btnSend').click(function(){
                    
                        $.ajax({
                        url : 'includes/thirdPopup.php',
                        type: 'post',
                        data: $('#formContent').serialize().done( function( ){  });
                });    
            });        
        </script>
        <?php
            
include 'includes/style.php';
            include 
'includes/script.php';
        
?>
    </head>
    <body>
        <div id="master">            
            <?php
                
include 'includes/portfolioHeader.php';
                include 
'includes/portfolioNavigation.php';
                include 
'includes/firstPopup.php';
                include 
'includes/secondPopup.php';
                include 
'includes/thirdPopup.php';
                include 
'includes/portfolioContent.php';
                include 
'includes/portfolioFooter.php';
            
?>
        </div>
    </body>
</html>


thirdPopup.php (include file containing email form):
PHP Code:
<?php
//thirdPopup.php
?>
<div id="popup3">
    <input type="image"  id="closePopup3" value="Send" src="img/close.png" onMouseOver="this.src='img/closeOver.png'" onMouseOut="this.src='img/close.png'" />
    <h1 class="popupHeading">Contact</h1>
    <div id="formContent">
        <?php
            
if ($posted == false){
        
?>
        <form name="contactForm" id="contactForm" action="<?=$_SERVER['PHP_SELF']?>" method="post">
            <fieldset>
                <table id="tableName">
                    <tr>
                        <td colspan="2">Name:</td>
                    </tr>
                    <tr>
                        <td id="nameInput">
                            <input type="text" name="name" id="name" value="<?=htmlspecialchars($name);?>" />
                        </td>
                        <td>
                            <?php
                                
if(isset($errMsg1) && !empty($errMsg1)){
                                    echo 
'<p id="error1">' $errMsg1 '</p>';    
                                }
                            
?>
                        </td>
                    </tr>
                </table>
                <table id="tableEmail">
                    <tr>
                        <td colspan="2">Email:</td>
                    </tr>
                    <tr>
                        <td id="emailInput">
                            <input type="text" name="email" id="email" value="<?=htmlspecialchars($email);?>" />
                        </td>
                        <td>
                            <?php
                                
if(isset($errMsg2) && !empty($errMsg2)){
                                    echo 
'<p id="error2">' $errMsg2 '</p>';    
                                }
                                if(isset(
$errMsg3) && !empty($errMsg3)){
                                    echo 
'<p id="error3">' $errMsg3 '</p>';    
                                }
                            
?>
                        </td>
                    </tr>
                </table>
                <table id="tableSubject">
                    <tr>
                        <td id="subjectLabel">Subject:</td>
                        <td>
                            <?php
                                
if(isset($errMsg5) && !empty($errMsg5)){
                                    echo 
'<p id="error5">(' $errMsg5 ')</p>';    
                                }
                            
?>
                        </td>
                    </tr>
                    <tr>
                        <td  colspan="2">
                            <input type="text" name="subject" id="subject" value="<?=htmlspecialchars($subject);?>" />
                        </td>
                    </tr>
                </table>    
                <table id="tableMessage">
                    <tr>
                        <td id="messageLabel">Message:</td>
                        <td>
                            <?php
                                
if(isset($errMsg6) && !empty($errMsg6)){
                                    echo 
'<p id="error6">(' $errMsg6 ')</p>';    
                                }
                            
?>
                        </td>
                    </tr>
                    <tr>
                        <td  colspan="2">
                            <textarea name="message" id="message" rows="7"><?=htmlspecialchars($msg);?></textarea>
                        </td>
                    </tr>
                </table>                            
                <table id="tableCaptcha">
                    <tr>
                        <td id="captchaLabel">Captcha Code:</td>
                        <td rowspan="2">
                            <img src="CaptchaSecurityImages.php?width=100&height=40&characters=5" id="captchaImg" />        
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="text" id="security_code" name="security_code" value="<?=htmlspecialchars($code);?>" />                        
                        </td>
                    </tr>
                </table>
                
                
                <table  id="tableSubmit">
                    <tr>
                        <td>
                            <input type="image" name="btnSend" id="btnSend" value="Send" width="106" height="59" src="img/send.png" onMouseOver="this.src='img/sendOver.png'" onMouseOut="this.src='img/send.png'" onmousedown="emailSubmitted()" />
                        </td>
                        <td>
                            <?php
                                
if(isset($errMsg4) && !empty($errMsg4)){
                                    echo 
'<p id="error4">' $errMsg4 '</p>';    
                                }
                            
?>
                        </td>
                    </tr>
                </table>
                
            </fieldset>
        </form>
        <?php ?>
        <?php
            
if(isset($feedback) && !empty($feedback)){
                echo 
'<p class="info">' $feedback '</p>';
            }
        
?>        
    </div>    
</div>




email.php (include file that validates and sends the email):
PHP Code:
<?php
session_start
();

$name "";
$email "";
$code "";
$subject "";
$msg "";
$valid true;
$posted false;
$errMsg1 "";
$errMsg2 "";
$errMsg3 "";
$errMsg4 "";
$errMsg5 "";
$errMsg6 "";
 
if(isset(
$_POST['email'])){
    
$name strip_tags(trim($_POST['name']));
    
$email strip_tags(trim($_POST['email']));
    
$subject strip_tags(trim($_POST['subject']));
    
$msg strip_tags(trim($_POST['message']));
    
$code strip_tags(trim($_POST['security_code']));    
    
    
    
/************************************
    PREVENTING HEADERS INSERTION
    *************************************/        
    
    
if( eregi("(multipart\alternative|content-type:|cc:|bcc:|boundary=)"$name )){
        die(
'Sorry but my email server does not like you.');    
    }else if( 
eregi("(multipart\alternative|content-type:|cc:|bcc:|boundary=)"$email )){
        die(
'Sorry but my email server does not like you.');    
    }else if( 
eregi("(multipart\alternative|content-type:|cc:|bcc:|boundary=)"$subject )){
        die(
'Sorry but my email server does not like you.');    
    }else if( 
eregi("(multipart\alternative|content-type:|cc:|bcc:|boundary=)"$msg )){
        die(
'Sorry but my email server does not like you.');    
    }  
    
    
    
/***************************************************
    PREVENTING INVALID EMAIL AND BLANK FIELDS
    ****************************************************/    
    
function is_valid_email($email) {
        
$result true;
        if((!
eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$"$email)) && ( !empty($email))) {
            
$result false;
        }
        return 
$result;
    }
    function 
is_valid_code($code) {
        
$result false;
        if( 
$_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {
            
// Insert you code for processing the form here, e.g emailing the submission, entering it into a database. 
            //echo 'Thank you. Your message said "'.$_POST['message'].'"';
            
unset($_SESSION['security_code']);
            
$result true;
        } else {
            
// Insert your code for showing an error message here
            //echo 'Sorry, you have provided an invalid security code';
            
$result false;
        }
        return 
$result;
    }
    if( empty(
$name)){
        
$valid false;
        
$errMsg1 "Your name?";
    }     
    if( empty(
$email)){
        
$valid false;
        
$errMsg2 "Your email?";
    }    
    if (!
is_valid_email($email) && !empty($email)){
        
$valid false;
        
$errMsg3 "Invalid email.";
    }
    if (!
is_valid_code($code)){
        
$valid false;
        
$errMsg4 "Please retype the captcha code and help me avoid getting email spam. Thanks.";
    }
    if( empty(
$subject)){
        
$valid false;
        
$errMsg5 "Please type in your subject.";
    }
    if( empty(
$msg)){
        
$valid false;
        
$errMsg6 "Please type in your message.";
    }
     
    if(
$valid){
        
//send the email    
            
$headers "From: $name <$email> \n";
            
$headers .= "Reply-To: $name <$email>";            
            
$subject trim($_POST['subject']);        
            
$msg trim($_POST['message']); 
            
$sendTheMail mail('myname@mail.com'$subject$msg$headers);
            
$feedback '<p id="emailSent">The email was successfully sent. <span>Thank you.</span></p>';
            
$posted true;
    }else{
        
//do not send the email    
    
}
}
?>