JSFiddle - React, Tailwind, and code Playground

HTML

<div id="html1">They kill me for waiting you. I can't recall a more bla bla bla bla

</div>

JavaScript

if (!window.x) {
    x = {};
}

x.Selector = {};
x.Selector.getSelected = function() {
    var t = '';
    if (window.getSelection) {
        t = window.getSelection();
    } else if (document.getSelection) {
        t = document.getSelection();
    } else if (document.selection) {
        t = document.selection.createRange().text;
    }
    return t;
}

$('#html1').ready(function() {
    $(document).bind("mouseup", function() {
        var mytext = x.Selector.getSelected();
        alert(mytext);
    });
});