HTML JS
(quick & simple examples)
USE JAVASCRIPT TO SUBMIT FORM <form id="myForm" onsubmit="return ajaxpost()"> <input type="text" name="name"> <input type="email" name="email"> <input type="submit" value="Go!"> </form>
function ajaxpost () { GET FORM DATA var data = new FormData(document. getElementById("myForm"));
AJAX POST fetch(URL, {method : "POST", body : data}) .then(res=>res.text())
SHOW MESSAGE ON RESPONSE .then(res => alert(res)); }
PROCESS & SHOW MESSAGE <?php if (isset($_POST["name"])) { require "PROCESS.PHP"; echo "<div>$message</div>"; } ?>
SUBMIT TO SAME PAGE <form method="post" target="_self"> <input type="text" name="name"> <input type="email" name="email"> <input type="submit" value="Go!"> </form>
DO WHATEVER PROCESSING REQUIRED. SAVE TO DATABASE, SEND EMAIL, ETC... FINALLY, SET A SYSTEM MESSAGE $message = "OK"; $message = "ERROR!";