how I use server without open anything?

<script>
function test() {
var name = document.getElementById('name').value;
document.cookie = "name=" + name;
console.log(document.cookie);
document.open('chk_name.php','chk_name','width=100, height=100');
} </script>

this is chk_name.php

<?php
echo "hi! this is chk_name.php";
echo $_COOKIE['name'];
// echo "<script>window.close();</script>";?>

I want to check username. I use document.open(‘chk_name.php’); then I check username in chk_name.php by using cookie. but I have problem when user using their phones. document.open make a new window. It looks Ok in PC browser. but It looks terrible in phone browser. because they make a full screen. so I want to check username without openning new window. how can I check data using server(db) wihtout openning new window?

Answer

You can use ajax request for this purpose

function loadDoc() {
  var xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      document.getElementById("demo").innerHTML = this.responseText;
    }
  };
  xhttp.open("GET", "chk_name.php", true);
  xhttp.send();
}