Change search fields to drop down menus

Hi all - pretty new to these forums....
Can anyone advise me - using efg - how to change the search fields to drop down (select) menus when the multiple search options is selected?

What I have is this:

<?php if ($this->search_form_type == 'multiplefields'): ?>
<input type="hidden" name="search" value="<?php echo $this->search_fields; ?>">
<?php foreach ($this->search_searchfields as $field): ?>
<div class="search_field <?php echo $field['name']; ?>">
<label for="search_for_<?php echo $field['name']; ?>"><?php echo $field['label']; ?></label>
<input type="text" id="search_for_<?php echo $field['name']; ?>" name="for[<?php echo $field['name']; ?>]" class="text" value="<?php echo $this->for[$field['name']]; ?>" list="destinations">


</div>

which works great for text searches... but I would like select menus instead of the search fields populated by the data in the table rows.

Any help welcome :)