javascript - Combine input box and select box to create a search bar -

i have input box serves search box, , populate select box querying sql database. example, there 2 organizations called "dummy organization" , "dummy 2" in db. when user starts typing "du", select box fills 2 organizations. want combine these 2 fields: input box (that acts search box) , select box (which displays results). research shows selectize.js can useful, since i'm new js, can't figure out how. can please me? code below:

js gets data db:

<script type="text/javascript"> function searchq(){     var searchtxt = $("input[name='search']").val();     $.post("search.php", {searchval: searchtxt},function(output4){         $("#output4").html(output4); } </script> 

the form:

<form action="newbrand.php" method="post" id="form">         <br>         brand name: <input type="text" name="bname" required /><br><br>         search organization: <input type="text" required  name="search" onkeyup="searchq()" id="output"><br><br>                  selected organization:         <select id="output4" name="taskoption"></select> </form> 

the search.php file

<?php include 'db_connect.php'; $link = mysqli_connect($host, $username, $password, $db);  if(!link){ echo "db connection error"; } $output = '' ; $output2 = '' ; if (isset($_post['searchval'])){ $searchq = $_post['searchval']; //$searchq = preg_replace("#[^0-9a-z]#i","",$searchq); $query = mysqli_query($link, "select * `organisations_info` `organisation_name`  '%".$searchq."%' ")or die("could not search!");  $count = mysqli_num_rows($query); if($count == 0){     $output = '<option>no results!</option>'; }else{     while($row = mysqli_fetch_array($query)){         $orgname = $row['organisation_name'];         $orgid = $row['organisation_id'];         $subs = $row['subscription_type'];     ?>     <option value="<?php echo $orgid; ?>"><?php echo $orgname; ?></option>     <div><?php echo $subs; ?></div>     <?php     } // while } // else } // main if ?>