<?php echo form_open(); ?>
    <select>
        <?php foreach($status_list as $status): ?>
        <option value="<?php echo $status->id; ?>"><?php echo $status->name; ?></option>
        <?php endforeach; ?>
    </select>
    <!-- Show this only if status type is, let's say "E" -->
    <input type="text" name="E_happened">
    <!-- Show this only if status type is, let's say "S" -->
    <input type="text" name="S_happened">
<?php echo form_close(); ?>