JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <head>
    </head>
    <body>
        <form id="leftTemplates" name="left" action="">
            <select id="templateSelect" onchange="showSelectedTemplate(this)">
            </select>
        </form>
    </body>
</html>

JavaScript

window.onLoad = buildSelect();

function buildSelect() {
        var labels = ["Please select a template...",
            "test1",
            "test2",
            "test3",
            "test4",
            "test5",
            "test6"
         ];

        for(var i=0; i<labels.length; i++) {
            var selectBox = document.getElementById('templateSelect');
            var newOption = document.createElement('option');
            newOption.label = labels[i];
            newOption.innerHTML = labels[i];
            newOption.value = labels[i];
            if(i==0) { newOption.setAttribute('selected','selected'); }
            selectBox.appendChild(newOption);
        }
    }
showSelectedTemplate = function(elem) {
   var selectedTemplate = elem.options[elem.options.selectedIndex].value;
    alert(selectedTemplate);
}