【解決方法】htmlをphpファイルにリンクする方法

親愛なるみんな

mailhandler という名前の php ファイルと html ファイルの連絡先フォームがあるので、
phpファイルをhtmlファイルにリンクする方法

ここにコードがあります

<?php
	$owner_email = $_POST["owner_email"];
	$headers = 'From:' . $_POST["email"];
	$subject = 'A message from your site visitor ' . $_POST["name"];
	$messageBody = "";
	
	if($_POST['name']!='nope'){
		$messageBody .= '<p>Visitor: ' . $_POST["name"] . '</p>' . "\n";
		$messageBody .= '<br>' . "\n";
	}
	if($_POST['email']!='nope'){
		$messageBody .= '<p>Email Address: ' . $_POST['email'] . '</p>' . "\n";
		$messageBody .= '<br>' . "\n";
	}else{
		$headers = '';
	}
	if($_POST['state']!='nope'){		
		$messageBody .= '<p>State: ' . $_POST['state'] . '</p>' . "\n";
		$messageBody .= '<br>' . "\n";
	}
	if($_POST['phone']!='nope'){		
		$messageBody .= '<p>Phone Number: ' . $_POST['phone'] . '</p>' . "\n";
		$messageBody .= '<br>' . "\n";
	}	
	if($_POST['fax']!='nope'){		
		$messageBody .= '<p>Fax Number: ' . $_POST['fax'] . '</p>' . "\n";
		$messageBody .= '<br>' . "\n";
	}
	if($_POST['message']!='nope'){
		$messageBody .= '<p>Message: ' . $_POST['message'] . '</p>' . "\n";
	}
	
	if($_POST["stripHTML"] == 'true'){
		$messageBody = strip_tags($messageBody);
	}
	
	try{
		if(!mail($owner_email, $subject, $messageBody, $headers)){
			throw new Exception('mail failed');
		}else{
			echo 'mail sent';
		}
	}catch(Exception $e){
		echo $e->getMessage() ."\n";
	}
?>

これがhtmlファイルです

<form id="contact-form">
          <div class="success"> Contact form submitted! We will be in touch soon. </div>
          <fieldset>
            <div>
              <label class="name">
                <input type="text" value="Name:">
                <br>
                <span class="error">*This is not a valid name.</span> <span class="empty">*This field is required.</span> </label>
            </div>
            <div>
              <label class="email">
                <input type="email" value="E-mail:">
                <br>
                <span class="error">*This is not a valid email address.</span> <span class="empty">*This field is required.</span> </label>
            </div>
            <div>
              <label class="phone">
                <input type="tel" value="Phone:">
                <br>
                <span class="error">*This is not a valid phone number.</span> <span class="empty">*This field is required.</span> </label>
            </div>
            <div>
              <label class="message">
                <textarea>Message:</textarea>
                <br>
                <span class="error">*The message is too short.</span> <span class="empty">*This field is required.</span> </label>
            </div>
            <div class="buttons-wrapper"><a class="button" data-type="reset">Clear</a><a class="button"  data-type="submit">Send</a></div>
          </fieldset>
        </form>