JSFiddle - React, Tailwind, and code Playground
by hicurin
HTML
<span id="spnTest">0</span>
<button id="btnTest" onclick="decrease();">Decrease</button>
JavaScript
var ratio = 5;
var totalValue = 500;
function decrease(){
alert('ok');
if(totalValue == 0) return;
totalValue -= ratio;
document.getElementById('spnTest').innerHTML = totalValue;
}