Searchform & results

Hwo can i make a good searchform with
t_region is a value in a post

searchform imput:

<?php global $t_sregion;
$t_sregion =  isset($custom["t_sregion"][0]) ? $custom["t_sregion"][0] : ''; ?>

<form method="get" id="searchform1" action="<?php echo home_url(); ?>">
					<input type="text" value="<?php esc_attr_e('','theme'); ?>" name="s" id="searchinput" /> <select id="t_sregion" name="t_sregion">
			<option value="">All regions</option>
			<?php foreach ($sregion as $key => $value) { ?>
				<option <?php if (htmlspecialchars($t_sregion) == $key) echo('selected="selected"')?> value="<?php echo esc_attr($key); ?>"><?php echo esc_html($value); ?></option>
			<?php }; ?>
		</select>
        <?php wp_dropdown_categories( $args ); ?>
        <input type="image" src="<?php bloginfo('template_directory'); ?>/images/search-icon.png" id="searchsubmit" />
				</form>

search results:

<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
			<div class="post clearfix">
				<?php $custom = get_post_custom($post->ID);
				if ( isset($_POST['t_region']) == $t_sregion )
				{

//searchform
//end

How can i do it?