JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
        <script src="Scripts/Scripts.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
       Choose Destinations: &nbsp <input type="text" id="destinations" name="destinations"/>
        &nbsp
        <br />
        <br />
        <div id="DestinationsChosen"></div>
    </div>
    </form>
</body>
</html>

JavaScript

$(function() {
    $("#destinations").autocomplete({
        select: function (event, ui) {
            $("#DestinationsChosen").html(function(i, origText)
            {
                var SelectedCountry = ui.item.value.toString();
                var CurrentText = origText.toString();
                if ((CurrentText.indexOf(SelectedCountry) >= 0))
                {
                    alert("Already Exists");
                    return CurrentText;
                }
                return CurrentText + " " + SelectedCountry;
            })
        }
    });
})



$(function() {
 
    $( "#destinations" ).autocomplete({
     source: function( request, response ) {
          var matcher = new RegExp( "^" + $.ui.autocomplete.escapeRegex( request.term ), "i" );
          response( $.grep( availableDestinations, function( item ){
              return matcher.test( item );
          }) );
      }
    })
});



var availableDestinations = [
"Afghanistan",
"Albania",
"Algeria",
"Andorra",
"Angola",
"Antigua and Barbuda",
"Argentina",
"Armenia",
"Australia",
"Austria",
"Azerbaijan",
"Bahamas",
"Bahrain",
"Bangladesh",
"Barbados",
"Belarus",
"Belgium",
"Belize",
"Benin",
"Bhutan",
"Bolivia",
"Bosnia and Herzegovina",
"Botswana",
"Brazil",
"Brunei",
"Bulgaria",
"Burkina Faso",
"Burundi",
"Cabo Verde",
"Cambodia",
"Cameroon",
"Canada",
"Central African Republic",
"Chad",
"Chile",
"China",
"Colombia",
"Comoros",
"Congo",
"Costa Rica",
"Cote d'Ivoire",
"Croatia",
"Cuba",
"Cyprus",
"Czech Republic",
"Denmark",
"Djibouti",
"Dominica",
"Dominican Republic",
"Ecuador",
"Egypt",
"El Salvador",
"Equatorial...