var http = false;
              
if(navigator.appName == "Microsoft Internet Explorer") {
	http = new ActiveXObject("Microsoft.XMLHTTP");
}
else {
	http = new XMLHttpRequest();
}

/*	Funkce kontroly spravnosti zadanych dat		*/
function login_exist(login) {
	http.abort();
	http.open("GET", "/ajax.php?login=" + login, true);
	
	http.onreadystatechange = function() {
		if(http.readyState == 4) {
			if(http.responseText == 'no'){
				alert('Nickname již existuje, zkuste jiný');
				document.getElementById('login').value = '';
				document.frm_reg.login.focus();
			}
//			document.getElementById('existence_nickname').innerHTML = http.responseText;
		}
	}
	http.send(null);
	
}