Email Sends When I enter A Certain Part of my Page - php

Question

I am having trouble with a contact form for my website. So there are two parts to this problem.
First I want to know how and why every time I enter the contact link of my page, it automatically sends an email, upon entering the page, and when clicking submit (I only want it to do this one) .
So example:
I go to mywebsite.com then I click on the 'Contact Us' link page. Upon taking me to the contact form, an e-mail is sent automatically. I am then allowed to fill out the form and send another e-mail. I want to know how to prevent that from happening and why it happens.
Second. I have seen lots of answered questions about this but none of the ones I have looked up on this website have worked for me so far.
When I click submit, to submit the form, it sends the email but then stays on the same page without clearing all fields or giving a confirmation message. I had also tried to redirect the page to say something like 'message has been sent successfully' or anything on the lines of that.
I am going to post my code below, but here are some notes on what I have tried before I do.
I tried to include a header to redirect after clicking submit. I am either doing that incorrectly or it just does not work.
I have tried the redirection with a java code, but since doing that it automatically sends an email then redirects to the page I stated without actually going to the contact form page.
My code is the php and html in one. I am going to separate the two after I finish it but I want to get it working first before I organize this section.
While looking at my code please do not judge. I am not a professional at this and I do understand that there are errors. I have tried to keep it with 0 errors but just have been adding code on top of code now to try and get this to work and may have added errors. I am open to suggestions in order to achieve the same effect while breaking down my code if possible. One error I do know I have is my form-inline statement. I am intentionally missing the quote at the end because with the quote, the search bar on my site gets messed up.
I have looked into jquery and ajax as well but I would prefer if someone give me a solution using the same format that I currently have the code in, unless the format is the problem I guess.
I changed my actual domain to mydomain.com for the example.
I do understand too that there may be a lot of irrelevant code but I am not sure if any line may be the problem so I tried to make clear what each section of code does for my page and included everything jsut in case one of those may be the problem.
<?php
$nameErr = $emailErr = $numberErr = $websiteErr = "";
$name = $email = $number = $comment = $subject = "";
$datetime = date('d/m/Y H:i:s');
$ipaddress = $_SERVER['REMOTE_ADDR'];
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["name"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["name"]);
}
if (! preg_match("/^[a-zA-Z ]*$/", $name)) {
$nameErr = "Only letters and white space allowed";
}
if (empty($_POST["email"])) {
$emailErr = "Email is required";
} else {
$email = test_input($_POST["email"]);
}
if (! filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Invalid email format";
}
if (empty($_POST["subject"])) {
$subject = "";
} else {
$subject = test_input($_POST["subject"]);
}
if (empty($_POST["number"])) {
$number = "";
} else {
$number = test_input($_POST["number"]);
}
if (empty($_POST["comment"])) {
$comment = "";
} else {
$comment = test_input($_POST["comment"]);
}
}
$email_message = "Form details below.\n\n";
function clean_string($string) {
$bad = array(
"content-type",
"bcc:",
"to:",
"cc:",
"href"
);
return str_replace($bad, "", $string);
}
$email_message .= "Full Name: " . clean_string($name) . "\n";
$email_message .= "E-mail: " . clean_string($email) . "\n";
$email_message .= "Subject: " . clean_string($subject) . "\n";
$email_message .= "ipaddress: " . clean_string($ipaddress) . "\n";
$email_message .= "date and time: " . clean_string($datetime) . "\n";
$email_message .= "Phone#: " . clean_string($number) . "\n";
$email_message .= "Message: " . clean_string($comment) . "\n";
$email_from = $name . '<' . $email_from . '>';
$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'From:' . $email_from . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
/* Send the message using mail() function */
$myemail = "contact#mydomain.com";
mail($myemail, $subject, $email_message, $headers);
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
sec_session_start();
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>My Domain - Contact</title>
<meta name="keywords" content="" />
<meta name="description" content="" />
<link href="../css/style.css" rel="stylesheet" type="text/css" media="screen" />
</head>
<body>
<div id="logo">
<h1><img src="../tab/mydoaminlogo.jpg" alt="" width="780" height="104" /></h1>
</div>
<hr />
<!-- end #logo -->
<div id="header">
<div id="menu">
<ul>
<li>Home</li>
<li class="current_page_item">News</li>
<li>Locations</li>
<li>About</li>
<li>Contact</li>
<?php if (login_check($mysqli) == true) : ?>
<li>Store</li>
<?php else: ?>
<li>LogIn</li>
<?php endif; ?>
<?php if (login_check($mysqli) == true) : ?>
<li>Log Out</li>
<?php else: ?>
<li>Sign-up</li>
</ul>
<?php endif; ?>
</div>
<!-- end #menu -->
<div id="search">
<form method="get" action="" class="form-inline>
<fieldset>
<input type="text" name="s" id="search-text" size="15" />
<input type="submit" id="search-submit" value="Search" />
</fieldset>
</form>
</div>
<!-- end #search -->
</div>
<!-- end #header -->
<!-- end #header-wrapper -->
<div id="page">
<div id="content_wide">
<div class="post">
<div class="entrycontact">
<div class="container">
<form id="contact" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method="post">
<h3>Contact Us</h3>
<h4>Please fill out completely</h4>
<fieldset>
<input placeholder="Your name" type="text" name="name" value="<?php echo $name;?>" tabindex="1" required autofocus>
<span class="error"> <?php echo $nameErr;?></span>
</fieldset>
<fieldset>
<input placeholder="Your Email Address" type="email" name="email" value="<?php echo $email;?>"tabindex="2" required>
<span class="error"> <?php echo $emailErr;?></span>
</fieldset>
<fieldset>
<input placeholder="Subject" type="tel" name="subject" value="<?php echo $subject;?>"tabindex="2" required>
<span class="error"><?php echo $numberErr;?></span>
</fieldset>
<fieldset>
<input placeholder="Number" type="tel" name="number" value="<?php echo $number;?>"tabindex="3" required>
<span class="error"><?php echo $numberErr;?></span>
</fieldset>
<fieldset>
<textarea placeholder="Type your message here...." name ="comment" tabindex="5" required><?php echo $comment;?></textarea>
</fieldset>
<fieldset>
<button name="submit" type="submit" id="contact-submit" data-submit="...Sending">Submit</button>
</fieldset>
</form>
</div>
</div>
</div>
</div>
<!-- end #content -->
<!-- end #sidebar -->
<div style="clear: both;"></div>
</div>
<!-- end #page -->
<div id="footer"></div>
<!-- end #footer -->
</body>
</html>