Else If loop in wordpress for dynamic banner

I have the following code as a Loop in my category.php page. Its showing a dynamic banner when its coming from home page to this paape. I tried to filter by slug. and put them in else if loop. There will be several pages. But its showing an error.

syntax error, unexpected 'elseif' (T_ELSEIF)

<?php if($category_slug=='abc-bed'){?>  
        <div id="catHero">
            <div id="blackPostBox"  class="<?php echo "cat_id_" . $category_slug?>"> 
                <h1 id="cath1"><?php echo $root[0]->post_title ?></h1>
                <hr class="color-strip">    
                <p><?php echo $text = apply_filters('the_excerpt', get_post_field('post_excerpt', $root[0]->post_content ));?></p>
                <div class="searchbar"><?php get_search_form(); ?></div>
            </div>
        </div>

    <?php elseif ($category_slug=='abc_efg') {?>
        # code...
    <?} ?>
    <?php else ($category_slug=='abc_rrg') {?>
        # code...
    <?} ?>
    <?php }?>