JSFiddle - React, Tailwind, and code Playground

HTML

<div class="red">
<div id="ddiv" class="blue">
    <table id="pio">
    <tr>
        <td>aaa</td>
    </tr>
    <tr>
            <td>bbb</td>
    </tr>
    </table>
</div>
</div>

CSS

.blue{
    margin:2em;
    padding:1em;
    border:1px solid lime;
    background-color:blue;
    color:yellow;
}

.red{
background-color:red;
    padding:3.3em;
}

JavaScript

function contains(padre, figlio) {
    var output = false;
    if (figlio && 'parentNode' in figlio) {
        var su = figlio;
        while (su = su.parentNode) {
            if (su == padre) {
                output = true;
                break;
            }
        }
    }
    return output;
}

function check(event) {
    //console.dir(event);
    var related = event.relatedTarget || event.toElement;
    if (related == null) return true;
    if (!related) return false;
    return (related != this && related.prefix != 'xul' && !contains(this, related));

}


var me = document.getElementById('ddiv');
me.onmouseout = function(e) {
    e = e || window.event;

        if ((e.target || e.srcElement) == me) {


        if (check.call(this, e)) {
            alert('ffff')
        }
    }

};

onerror = function(a, b, c) {
    alert(a + ' ' + b + ' ' + c)
}