JSFiddle - React, Tailwind, and code Playground

HTML

<!-- tags container -->
    <div class="container_12">
        <div class="grid_2"><img src="images/spacer.png" /></div>
        <div id="content" class="grid_8">
            <button name="PHP" class="tag-button" >PHP</button>
        </div>
        <div class="grid_2"><img src="images/spacer.png" /></div>
    </div>
    <!-- tags container end -->

    <!-- action buttons container -->
    <div class="container_12 action-bar">
        <div class="grid_4"><img src="images/spacer.png" /></div>
        <div id="action-add">
            <input type="text" name="newTag" id="newTag" />
            <input type="button" id="add" value="Add tag" />
        </div>
        <div class="grid_4"><img src="images/spacer.png" /></div>
        <div id="action-edit">
            <input type="text" name="editTag" id="editTag" />
            <input type="button" id="update" value="Update tag" />
        </div>
    <!-- action buttons container end -->
    </div>

    <!-- Real Time list container -->
    <div class="container_12">
        <div class="grid_4"><img src="images/spacer.png" /></div>
        <select id="insertString">
            <option value="0">CSS</option>
            <option value="1">PHP</option>

        </select>
    </div>
    <!-- real time list container end -->

JavaScript

$(".tag-button").click(function(){
    var name = $(this).attr('name');
    $('#insertString option:contains("'+ name + '")').attr('selected', true);
});