I need to help with this code. I have a form. Submitted data is saved in XML file and then inserted into the table below the form. I have created “edit” and “delete” button for each line of the table, but I can not solve How to make “edit” button functional?? Here is a part of HTML:

  <form action="" method="POST">   <input type="hidden" name="id" value=""/>   <p>fname:</p>   <input type="text" name="fname"/><span class="error"><?php echo $  errors['fname'] ?></span>   <p>lname:</p>   <input type="text" name="lname"/><span class="error"><?php echo $  errors['lname'] ?></span>   <p>street:</p>   <input type="text" name="street"/><span class="error"><?php echo $  errors['street'] ?></span>   <p>city:</p>   <input type="text" name="city"/><span class="error"><?php echo $  errors['city'] ?></span>   <p>postcode:</p>   <input type="text" name="postcode"/><span class="error"><?php echo $  errors['postcode'] ?></span>   <p>country:</p>   <input type="text" name="country"/><span class="error"><?php echo $  errors['country'] ?></span>   <p>e-mail:</p>   <input type="text" name="email"/><span class="error"><?php echo $  errors['email'] ?></span>   <p>phone:</p>   <input type="text" name="phone"/><span class="error"><?php echo $  errors['phone'] ?></span>    <input type="submit" value="SUBMIT"/>  </form>  <?php   $  document = new DOMDocument("1.0", "utf-8");   if (is_file('form_data.xml')) {         $  document->load("form_data.xml");         $  users= $  document->getElementsByTagName("user");            echo "<table>";              echo '<tr>';             foreach($  users->item(0)->childNodes as $  data) {                 echo "<th>".$  data->nodeName."</th>";             }             echo "</tr>";              foreach($  users as $  key => $  user){                 echo "<tr>";                 foreach($  user->childNodes as $  data) {                     echo "<td>". $  data->nodeValue ."</td>";                 }                     echo "<td>                           <a href='?id={$  key}&action=edit' class='buttons edit'>EDIT</a>                           <a href='?id={$  key}&action=delete' class='buttons delete'>&#10006</a>                           </td>";                 echo "</tr>";             }            echo "</table>";    } 

And here is a part of code from functions.php file :

  switch ($  _GET['action']){     case 'edit':         // I need to make this part         break;     case 'delete':         $  document = new DOMDocument("1.0", "utf-8");         $  document->load("form_data.xml");         $  user= $  document->getElementsByTagName('user')->item($  _GET['id']);         $  user->parentNode->removeChild($  user);         $  document->save("form_data.xml");         break;   } 

Edited data should be inserted back to the form. Is there anybody who can help me? Thanks in advance!