JSFiddle - React, Tailwind, and code Playground

HTML

<label id=count_label_ms></label>
<br>
<p>
    <input type=button value="Start" onclick="start()" />
    <input type=button value="Pause" onclick="pause()" />
    <input type=button value="Reset" onclick="reset()" />
    <input type=button value="Stop" onclick="stop()" />
</p>

JavaScript

var params = {
               countms:0,
               intervalTxt:null,
               id: "count_label_ms",
               startInit:1,
               type: "s"
             }; 

function start() {
            if (params.intervalTxt == null) {
                params.intervalTxt = setInterval(function() {
                params.countms++;
                var content = parseFloat(params.countms) / 100 + " "+params.type;    
                document.getElementById(params.id).innerHTML = content ;
               }, params.startInit);
            }
}

function pause() {
         if (params.intervalTxt != null) {
            clearInterval(params.intervalTxt);
            params.intervalTxt = null;
          }
}

function reset() {
     clearInterval(params.intervalTxt);
     params.intervalTxt = null;
     params.countms = 0;
     var content = 0 + " "+params.type;    
     document.getElementById(params.id).innerHTML = content;
     start();
}

function stop() {
     clearInterval(params.intervalTxt);
     params.intervalTxt = null;
     params.countms = 0;
     var content = 0 + " "+params.type;    
     document.getElementById(params.id).innerHTML = content;
}