oneMoreTime

-----HTML----
<label>
	Korisničko ime
</label>
<br>
<input type="text" name="korIme" id = "korIme" placeholder="ivoIvic69">
<label id = "korImeE"></label>
<br>
<br>


---jQuery.js-----
$(document).on("change","#korIme",function(){
	var txt = $("#korIme").val();
	if(txt != "")
		$.get("registracija.php", {source: "korIme", korIme: txt}, function(res) {
			res = JSON.parse(res);
			if(res == "FAIL")
				$("#korImeE").text("Korisničko ime je zauzeto");
			else
				$("#korImeE").empty();
		});
	else
		$("#korImeE").empty();
});


----php-----
$input = $_GET["source"];
if($input == "korIme") {
	$korIme = $_GET["korIme"];
	$upit = "SELECT * from korisnici where korisnicko_ime = '".$korIme."'";
	$rez = $baza->selectDB($upit);
	$row = $rez->fetch_assoc();

	$stanje = "";
	if($row == null) {
		$stanje = "OK";
	} else
		$stanje = "FAIL";

	echo json_encode($stanje);
}