JSFiddle - React, Tailwind, and code Playground

HTML

<div style="width:100px;height:100px;border: solid;"></div>
<div id="menu" style="width:100px;height:100px;border: solid;" oncontextmenu="return false;"></div>

CSS

a:link {color: #000000 ; text-decoration: none; font-family: Verdana;font-size:8pt;}
	a:visited {color: #0c2b86 ; text-decoration: none; font-family: Verdana;font-size:8pt;}
	a:hover {color: #555555 ; text-decoration: underline; }
	a:active {color: #333333 ;text-decoration: underline;font-size:8pt; }
	img  { border : 0 }

JavaScript

var mouse_x = 0;
var mouse_y = 0;
var mouse_left = false;
var mouse_right = false;
var area = document.getElementById("menu");
if (area.addEventListener !== undefined) area.addEventListener('mousemove', mouseMove, true);
else if (area.layers) area.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP);
area.onmousemove = mouseMove;
area.oncontextmenu = RightMouseDown;
area.onmousedown = mouseDown;
document.onmouseup = mouseUp;

function mouseMove(a) {
    mouse_x = document.all ? event.clientX + document.body.scrollLeft : document.layers ? a.x + window.pageXOffset : a.clientX + window.pageXOffset;
    mouse_y = document.all ? event.clientY + document.body.scrollTop : document.layers ? a.y + window.pageYOffset : a.clientY + window.pageYOffset;
}

function RightMouseDown() {
    mouse_right = true;
    return false;
}

function init(a, w) {
    var b = document.createElement("DIV");
    b.id = "contextmenu";
    b.oncontextmenu = RightMouseDown;
    if (!w) w = 120;
    b.style.width = w + "px";
    var c = '<div oncontextmenu="return false;">';
    c += a;
    c += ' <a href="http://lablogic.net/scripts/contextmenu/right-click-menu.php" target="_top" title="javascript contextmenu" alt="Free javascript menu"><font color="#565656" size="-2">Get it...</font></a>';
    c += '</div>';
    b.innerHTML = c;
    b.style.position = "absolute";
    b.style.left = "0px";
    b.style.top = "0px";
    b.style.visibility = "hidden";
    b.style.overflow = "hidden";
    b.style.padding = "4px";
    b.style.backgroundColor = "#ffffff";
    b.style.border = "1px solid #6a6868";
    document.body.appendChild(b);
}

function mouseUp(e) {
    if (e.which == 1) document.getElementById("contextmenu").style.visibility = "hidden";
    else if (e.which == 3) mouse_right = false;
}

function mouseDown(e) {
    if (e.which == 3) {
        mouse_right = true;
        document.getElementById("contextmenu").style.left = mouse_x + "px";
       ...