[Wordpress Form hide after submittion]

I have this wordpress plugin im working on but what i want it to do is to hide the form on submit but its not working its still showing the form can anbody help. I am wanting to hide the form after submition

define('WP_DEBUG',true);
define('dtni_REGISTRATION_INCLUDE_URL', plugin_dir_url(__FILE__).'includes/');
ob_start();


//add front end css and js
function dtni_slider_trigger(){
	wp_enqueue_style('dtni_css_and_js', dtni_REGISTRATION_INCLUDE_URL."front-style.css"); 
    wp_register_script('dtni_css_and_js', dtni_REGISTRATION_INCLUDE_URL."font-script.js" );
	wp_enqueue_script('dtni_css_and_js');
}
add_action('wp_footer','dtni_slider_trigger');

// function to registration Shortcode
function dtni_registration_shortcode( $atts ) {
    global $wpdb, $user_ID; 
	$firstname='';
	$lastname='';
	$username='';
	$email='';
	
	/* //if looged in rediret to home page
	if ( is_user_logged_in() ) { 
	    wp_redirect( get_option('home') );// redirect to home page
		exit;
	} */
 
	if(sanitize_text_field( $_POST['com_submit']) != ''){

		$keresztnév=sanitize_text_field( $_REQUEST['com_firstname'] );
		$családnév=sanitize_text_field( $_REQUEST['com_lastname'] );
		
		$username = sanitize_text_field(  $_REQUEST['com_username'] );
		$email = sanitize_text_field(  $_REQUEST['com_email']  );
		$password = $wpdb->escape( sanitize_text_field( $_REQUEST['com_password']));
		$status = wp_create_user($username,$password,$email);
	    $succress ='';
		$error_msg='';
	   
		if (is_wp_error($status))  {
		     $error_msg = __('Username or Email already registered. Please try another one.',''); 
		} 
		else{
			$user_id=$status;
			update_user_meta( $user_id,'first_name', $fullname);
		 	update_user_meta( $user_id,'last_name', $családnév);
		 
			$succress= __('Your are register successfully for this site.',''); 
			
			$user_info=get_userdata( $user_id );
			
			wp_mail($user_info->user_email, 'User first and last name', sprintf('Hi we have added your first name :-% and last name:- % to our site.',$_POST['fullname']));

			
		}  
	}
  
		 ?>
	 
	<div class="digtalthinkersni-registration-form">
		 
		<?php if($error_msg!='') { ?><div class="error"><?php echo $error_msg; ?></div><?php }  ?>
		<?php if($succress!='') { ?><div class="success"><?php echo $succress; ?></div><?php }  ?>
		
		<form  name="form" id="registration"  method="post">
			<div class="ftxt">
			 <label><?php _e("Keresztnév: *",'');?></label> 
			 <input id="com_firstname" name="com_firstname" type="text" class="input" required value=<?php echo $keresztnév; ?> > 
			</div><div class="ftxt">
			 <label><?php _e("Családnév: *",'');?></label> 
			 <input id="com_fullname" name="com_lastname" type="text" class="input" required value=<?php echo $családnév; ?> > 
			</div>
			
			<div class="ftxt">
			 <label><?php _e("Felhasználói név :*",'');?></label> 
			 <input id="com_username" name="com_username" type="text" class="input" required value=<?php echo $username; ?> >
			</div>
			<div class="ftxt">
			<label><?php _e("E-mail: *",'');?> </label>
			 <input id="com_email" name="com_email" type="email" class="input" required value=<?php echo $email; ?> >
			</div>
			<div class="ftxt">
			<label><?php _e("Jelszó :*",'');?></label>
			 <input id="password1" name="com_password" type="password" required class="input" />
			</div>
			<div class="ftxt">
			
			 <input id="password2" name="c_password" type="password" class="input" />
			 <label><?php _e("Jelszó még egyszer: * ",'');?></label>
			</div>
			<div class="ftxt">			
			<label>
	
	<?php _e("Newsletter Signup : ",'');?>
	<input type="checkbox" name="mc4wp-subscribe" value="1" />
</label>
			</div>
			<input type="hidden" name="action" id="action" value="hideme" />
			
			<div class="fbtn"><input type="submit" name='com_submit' class="button"  value="<?php _e("Regisztráció",'');?>"/> </div>
		</form>
	</div>
<?php	
}


//add registration shortcoode
add_shortcode( 'digtialthinkers-registration-form', 'dtni_registration_shortcode' );
	
?>