KLIENT

function checkUser(name, password) {

	http = XMLHttpRequest()
	http.SetRequestHeader("content-type", "application/x-www-form-urlencoded")

	var phpfile = "file.php"
	var params = "user=name&password=password"

	http.open("POST", file.php, 1)
	http.post(params)

	http.onReadyStateChange = func() {
		if (http.readyState == 4 && http.status = 200) {
			NECO UDELEJ
		}
	}
}

SERVER
<?php
	if ($_POST) {
		ZISKEJ HESLO
		if ($_POST) == $heslo {
			TED CO ?
		}
 	}
?>