Я хочу отправить запрос на отправку и получить эхо из файла php. Но я не могу найти ошибку, всегда получите уведомление не определено индекс ...ошибка при отправке запроса POST через ajax
пожалуйста, не JQuery ...
<form id="register" method="POST" action="register-action.php">
<input type="text" name="first_name" placeholder="Onoma"><br>
<input type="text" name="last_name" placeholder="Epitheto"><br>
<input type="text" name="mail" placeholder="E-mail"><br>
<input type="password" name="pass" placeholder="password"><br>
<select name="eidikotita_id">
<?php while($eid = $eidikotites->fetch(PDO::FETCH_ASSOC)):
echo "<option value={$eid['id_eidikotitas']}>{$eid['titlos']}</option>";
endwhile; ?>
</select>
<input type="submit" value="Register"><br>
</form>
//////////////// ///////////////////////////////////////////////
var mail_input = document.querySelector("#registerinput[name='mail']").value;
alert(mail_input);
document.querySelector("#register input[name='first_name']").focus();
document.querySelector("#register input[name='mail']").onblur = function() {
var request = new XMLHttpRequest();//instantiate an XMLHttpRequest object
request.open("POST", "register-action.php", true);//Specifying the Request
request.setRequestHeader("Content-Type", "text/plain");//POST requests,for example, need a “Content-Type” header
request.send(mail_input);//specify the optional request body. GET requests never have a body, so you should pass null or omit the argument.
};
////////////////////////////////////////////// ///////////////////////////////
<?php
echo $_POST['mail'];
?>