iletişim formu zorunlu alan

<?php
/*
Template Name: Talep Formu
*/
?>
<?php get_header(); ?>    
    <div id="globalContainer" class="grid01">                            
        <div class="grid02 mTop20 mBottom20 mAuto">
            <hr class="rool" />
        </div>        
        <div class="clear"></div>        
        <div id="mainHeadline" class="grid03 mTop10 mAuto pLeft15 pRight15">
            <?php wp_reset_query(); if (have_posts()) : while (have_posts()) : the_post(); ?>                
                <div class="text"><?php the_title(); ?></div>
            <? endwhile;endif; ?>
        </div>
        <div class="clear"></div>
        <div id="mainProduct" class="grid01 mTop20">
            <div class="grid03 mAuto pLeft15 pRight15">
                <div class="productList archive single">
                    <?php
                    if(isset($_POST['gonder']))
                    {
                        $ad = $_POST['ad'];
                        $mail = $_POST['mail'];
                        $adres = $_POST['adres'];
                        $ilce = $_POST['ilce'];
                        $il = $_POST['il'];
                        $tel = $_POST['tel'];
                        $gsm = $_POST['gsm'];
                        $faks = $_POST['faks'];
                        $marka = $_POST['marka'];
                        $ariza = $_POST['ariza'];
                        $taleb = $_POST['taleb'];    
                        $icerik = 'İsim / Firma : ' . $ad . '<br />
                                    Mail : ' . $mail . '<br />
                                    Adres : ' . $adres . '<br />
                                    İlçe : ' . $ilce . '<br />
                                    İl : ' . $il . '<br />
                                    Tel : ' . $tel . '<br />
                                    Gsm : ' . $gsm . '<br />
                                    Faks : ' . $faks . '<br />
                                    Marka / Model : ' . $marka . '<br />
                                    Arıza : ' . $ariza . '<br />
                                    Talep : ' . $taleb;
                                    
                        $articleOption = array();
                        $articleOption['post_title'] = 'Arıza : '.$marka.'[ '.$ad.' ]';
                        $articleOption['post_type'] = 'talep';
                        $articleOption['post_content'] = $icerik;                        
                        $articleOption['post_status'] = 'pending';                    
                        $articleOption['post_author'] = 1;
                        
                        if ($post_id = wp_insert_post($articleOption))
                        {
                            //mysql_query("UPDATE wp_posts SET post_content= '" . $icerik . "' WHERE id='" . $post_id . "'");                         
                            echo '<div class="succ">Talebiniz Alınmıştır. Yetkili Arkadaşlarımız En Kısa Sürede Size Geri Dönüş Yapacaktır.</div>';
                        }else{
                            echo '<div class="error">Bir Hata Oluştu. Lütfen Daha Sonra Tekrar Deneyiniz.</div>';
                        }        
                    }
                    ?>
                    <form action="" method="post">
                            <div class="talep-formu">
                            <span class="input">
                                <input type="text" class="input__field" id="input-1" value="<?php echo $ad; ?>" name="ad"/>
                                <label for="input-1" class="input__label" >
                                    <span class="input__label-content">Ad Soyad / Firma Adı</span>
                                </label>
                            </span>
                            
                              <span class="input">
                                <input type="text" class="input__field" id="input-2" value="<?php echo $mail; ?>" name="mail"/>
                                <label for="input-2" class="input__label">
                                  <span class="input__label-content">E-Posta</span>
                              </label>
                              </span>
                            
                              <span class="input">
                                <input type="text" class="input__field" id="input-3" value="<?php echo $adres; ?>" name="adres"/>
                                <label for="input-3" class="input__label">
                                  <span class="input__label-content">Adres</span>
                              </label>
                              </span>
                            
                              <span class="input">
                                <input type="text" class="input__field" id="input-4" value="<?php echo $ilce; ?>" name="ilce"/>
                                <label for="input-4" class="input__label">
                                  <span class="input__label-content">İlçe</span>
                              </label>
                              </span>
                              <span class="input">
                                <input type="text" class="input__field" id="input-5" value="<?php echo $il; ?>" name="il"/>
                                <label for="input-5" class="input__label">
                                  <span class="input__label-content">İl</span>
                              </label>
                              </span>
                              <span class="input">
                                <input type="text" class="input__field" id="input-6" value="<?php echo $tel; ?>" name="tel"/>
                                <label for="input-6" class="input__label">
                                  <span class="input__label-content">Telefon</span>
                              </label>
                              </span>
                              <span class="input">
                                <input type="text" class="input__field" id="input-7" value="<?php echo $gsm; ?>" name="gsm"/>
                                <label for="input-7" class="input__label">
                                  <span class="input__label-content">GSM</span>
                              </label>
                              </span>
                              <span class="input">
                                <input type="text" class="input__field" id="input-8" value="<?php echo $faks; ?>" name="faks"/>
                                <label for="input-8" class="input__label">
                                  <span class="input__label-content">FAKS</span>
                              </label>
                              </span>
                              <span class="input">
                                <input type="text" class="input__field" id="input-10" value="<?php echo $marka; ?>" name="marka"/>
                                <label for="input-10" class="input__label">
                                  <span class="input__label-content">Marka / Model</span>
                              </label>
                              </span>
                              <span class="input message">
                                <textarea class="input__field" id="input-11" name="ariza"><?php echo $ariza; ?></textarea>
                                <label for="input-11" class="input__label">
                                  <span class="input__label-content">Arıza Durumu / Sebebi</span>
                              </label>
                              </span>
                              
                              <span class="input message">
                                <textarea class="input__field" id="input-12" name="taleb"><?php echo $taleb; ?></textarea>
                                <label for="input-12" class="input__label">
                                  <span class="input__label-content">Talebiniz</span>
                              </label>
                              </span>
                            
                              <input type="submit" name="gonder"id="send-button" value="Gönder" />
                            
                        </div>
                    </form>
                </div>                
            </div>
        </div>        
    </div>
<?php get_footer(); ?>

üstadlar elimde böyle bir taslak var ben bu form da herseyin zorunlu alan olmasını ve benim belirledigim bir mail adresine gönderilmesini istiyorum fakat bir türlü düzenleyemedim yardımcı olurmusunuz