Is this possible to accomplish with html and php? -

i've made form below. possible make when user enters number of fields, example 6, table below has 6 rows. great if possible make without submit button (so trigger action exiting text input box).

here html code of form:

<fieldset>   <legend>student information</legend>   number of fields: <input type="text"><br />   total number of characters: <input type="text">   <br>   <br>   <table border="1">     <th></th>     <th>field</th>     <th>number of characters</th>     <tr>         <td>1</td>         <td><input type="text"></td>         <td><input type="text"></td>     </tr>     <tr>         <td>2</td>         <td><input type="text"></td>         <td><input type="text"></td>     </tr>   </table>    </fieldset> 

if not possible (without submit button), in way accomplish same result? thank and/or suggestions.

okay here post script require

<?php   $rows=2;   if(isset($_post['submit']))   {     if($_post['submit']=='update')     {         if(isset($_post['rows'])) $rows=max($rows, intval($_post['rows'])); // minimum 2 rows     }     else     {         // process posted data here          // reset post or jump page         $_post=array();         //header("location:index.php");         //exit();     }   } ?> <form method="post"> <fieldset>   <legend>student information</legend>   number of fields: <input type="text" name="rows" value="<?php echo $rows; ?>"><br />   total number of characters: <input type="text">   <input type="submit" name="submit" value="update"/>   <br>   <br>   <table border="1">     <th></th>     <th>field</th>     <th>number of characters</th>     <?php         for($loop=1;$loop<=$rows;$loop++)         {             echo '<tr>';             echo '<td>'.$loop.'</td>';             echo '<td><input name="field['.$loop.']" value="'.$_post['field'][$loop].'" /></td>';             echo '<td><input name="chars['.$loop.']" value="'.$_post['chars'][$loop].'" /></td>';             echo '</tr>';         }     ?>   </table>   <input type="submit" name="submit" value="submit"/>   </fieldset> </form> 

it default 2 rows (minimum), , retain data when update rows.
if rows reduced, end ones disappear