Problème HTML/PHP ( Contact )

       <a name="contact"></a> 
             
            <h2>Contactez-Moi</h2> 
             
            <form action="" method="post" id="contactform"> 
                <div id="name-wrap" class="slider">  
                    <label for="name">Nom</label>  
                    <input type="text" id="name" name="name" />  
                </div><!--//name-wrap-->  
                 
                <div id="email-wrap"  class="slider">  
                    <label for="email">E-mail</label>  
                    <input type="text" id="email" name="email" />  
                </div><!--//email-wrap--> 
                 
                <div id="phone-wrap"  class="slider">  
                    <label for="phone">Sujet</label>  
                    <input type="text" id="phone" name="phone" />  
                </div><!--//phone-wrap-->  
                 
                <div id="url-wrap"  class="slider">  
                    <label for="url">SiteWeb</label>  
                    <input type="text" id="url" name="url" />  
                </div><!--//email-wrap-->  
                 
                <div id="comment-wrap"  class="slider">  
                    <label for="comment">Commentaires</label>  
                    <textarea cols="53" rows="10" id="comment"></textarea>  
                </div><!--//comment-wrap-->  
                 
                <div><button type="submit" id="btn" name="btn">Envoyer</button></div> 
                 
            </form>