?>

<label for=email>email:</label>

<input id="email" style="color:#000;">

<h2 id="result"></h2>



<script type="text/javascript">

function validateEmail(email) {

   const re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,4}))$/;

   //const re = /^[-0-9A-Z_\.]{1,50}@([-0-9A-Z_\.]+\.){1,50}([0-9A-Z]){2,4}$/;

   return re.test(email);

}

function validate() {

   const $result = $("#result");

   const email = $("#email").val();

   //const email = $('.select2-match span').html();

   $result.text("");

   if (validateEmail(email)) {

      $result.text(email + " is valid :)");

      $result.css("color", "green");

   } else {

      $result.text(email + " is not valid :(");

      $result.css("color", "red");

   }

   return false;

}

$("#email").on("input", validate);



</script>

<?php