I’m trying to build a custom search form for one of my pages. I need the search form to be able to search for users. Not only will it need to search for users, but by first name, last name etc.. Something similar to this:

The default WP search doesn’t allow for me to search users on my site. I’m using the plugin ‘Search Everything’ and still can’t manage to get any user data to show up in my searches.

Any help is much appreciated.

EDIT

Here is my form:

<?php 
    global $wpdb;
    $authors = $wpdb->get_results("SELECT ID, display_name FROM $wpdb->users WHERE user_nicename != 'admin' ORDER BY display_name LIMIT 10"); 
?>

<form action="<?php bloginfo('siteurl'); ?>" id="memberform" method="get">
    <div class="first_name">
        <select id="firstNameDrop" name="s">
            <option selected value="First Name">First Name</option>
            <?php
                foreach($authors as $author) {
                    $author_info = get_userdata($author->ID);
                    $name = $author_info->first_name;
                    echo '<option value="'.$name.'">'.$name.'</option>';
                }
            ?>
        </select>
    </div>
    <input type="submit" class="submit" name="submit" value="Search" />
</form>

This allows me to have my dropdown box with all of the users sorted by first name, and when I hit search, it takes me to my search page and pulls all posts corresponding to my search. That’s all fine and dandy, but I need it to ONLY pull in the users information – such as first name, last name, avatar, description etc.. and NOT posts.