JSFiddle - React, Tailwind, and code Playground

HTML

<!--Best if you inject the button element with javascript if you plan to support users with javascript disabled-->
<script>
insertHTML('<button class="click-me" id="btn1">Button 1</button>');
</script>

<!--Use this when you don't care about broken buttons when javascript is disabled.-->
<!--buttons can be used outside of forms http://stackoverflow.com/a/14461672/175071 -->
<button class="click-me" id="btn2">Button 2</button>
<input class="click-me" type="button" value="Button 3" id="btn3">

<!--Use this when you want to lead the user somewhere when javascript is disabled-->
<a class="click-me" href="/path/to/non-js/action" id="btn4">Button 4</a>

JavaScript

(function(doc){
    var cb_addEventListener = function(obj, evt, fnc) {
        // W3C model
        if (obj.addEventListener) {
            obj.addEventListener(evt, fnc, false);
            return true;
        } 
        // Microsoft model
        else if (obj.attachEvent) {
            return obj.attachEvent('on' + evt, fnc);
        }
        // Browser don't support W3C or MSFT model, go on with traditional
        else {
            evt = 'on'+evt;
            if(typeof obj[evt] === 'function'){
                // Object already has a function on traditional
                // Let's wrap it with our own function inside another function
                fnc = (function(f1,f2){
                    return function(){
                        f1.apply(this,arguments);
                        f2.apply(this,arguments);
                    }
                })(obj[evt], fnc);
            }
            obj[evt] = fnc;
            return true;
        }
        return false;
    };
    var hasClass = function(el,className) {
        return (' ' + el.className + ' ').indexOf(' ' + className + ' ') > -1;
    }

    cb_addEventListener(doc, 'click', function(e){
      if(hasClass(e.target, 'click-me')){
          e.preventDefault ? e.preventDefault() : e.returnValue = false;
          doSomething.call(e.target, e);
      }
    });
})(document);

function insertHTML(str){
  var s = document.getElementsByTagName('script'), lastScript = s[s.length-1];
  lastScript.insertAdjacentHTML("beforebegin", str);
}

function doSomething(event){
  alert(this.id); // this will be the clicked element
}