dropdown search form for registered user

I am having problem with the form on how I passed the search string for the users selection.

<form role=”search” method=”get” id=”searchform” action=”<?php bloginfo(‘url’); ?>”>
<div>
<label class=”screen-reader-text” for=”s”>Search for:</label>

<select name=”pros” id=”type” class=”postform”>
<option value=”” selected=”selected”>– Search a Pros — </option>
<option value=”pros: Accountants”>Attorney</option>
<option value=”pros: Engineers”>Financial Pros</option>
<option value=”pros: Doctors”>Counselors</option>
</select>

<select name=”gender”>
<option value=”” selected=”selected”> — Select Gender — </option>
<option value=”gender: male”>Male</option>
<option value=”gender: female”>Female</option>
</select>

<input type=”submit” id=”searchsubmit” value=”Search” />

<?php
$blogusers = get_users(‘search=john’);
foreach ($blogusers as $user) {
echo ‘
• ‘ . $user->user_email . ‘

‘;
}
?>

</div>
</form>

This is what I am trying to get through.

$blogusers = get_users(‘search=accountants&&male’);

How to pass the search string dynamically for the users selection.