JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" value="Start" id="start"/>
<input type="button" value="Stop"  id="stop"/>
<div id="mesage" display="none";>
    Всеки ден научавам JavaScript все по-добре!Мога да пиша код!
</div>

JavaScript

var workingFlag = false; 

$("#start").on( "click", function() {
     workingFlag = true;
     showMessage();
});

$("#stop").on( "click", function() {
     workingFlag = false;
});

function showMessage() {
    if (workingFlag == false) {
        return;
    }
    
    $("#mesage").show(0, function() {
        $(this).hide(0, function() {
            setTimeout(showMessage,1);
        });
    });
}