JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
         <legend>Get Data Ajax</legend>
         <form name="ajax" method="get" action="getData.php">
             <input type="text" name="getName" id="getName">
         </form>
         <div class="resBox" id="resBox"></div>
</fieldset>

JavaScript

el = document.body;
if (typeof el.addEventListener != "undefined") {
    el.addEventListener("keydown", function(evt) {
        doThis(evt.keyCode);
    }, false);
} else if (typeof el.attachEvent != "undefined") {
    el.attachEvent("onkeydown", function(evt) {
        doThis(evt.keyCode);
    });
}

function doThis(key) {
    switch (key) {
        case 13:
            alert('enter pressed');
            break;
        case 27:
            alert('esc pressed');
            break; 
        case 38:
            alert('up pressed');
            break;
        case 40:
            alert('down pressed');
            break;
    }
}