FERTIG

if(isset($_POST["submit"])){
		if(empty($_POST["username"]) || empty($_POST["password"])){
			$empty_fields = array();
			$empty_fields['error'] = "<div style=\"background: #c0392b; text-align: center; padding: 10px; border: 1px solid #2c3e50; box-shadow: 0 0 5px #2c3e50;\"><font color=\"white\">Bitte alle Felder ausf&uuml;hlen.</font></div>";
		}else{
			if(mysql_num_rows(mysql_query("SELECT * FROM users WHERE username = '".mysql_real_escape_string($_POST["username"])."' AND password = '".mysql_real_escape_string(sha1(sha1($_POST["password"])))."'")) > 0){
				$empty_fields['true'] = "<font color=\"green\">Du bist erfolgreich eingeloggt.</font>";
				$user = mysql_fetch_object(mysql_query("SELECT * FROM users WHERE username='".mysql_real_escape_string($_POST['username'])."'"));
				$_SESSION["username"] = mysql_real_escape_string($user->username);
				$_SESSION["password"] = sha1(sha1($_POST["password"]));
				header("location:./home");
				mysql_query("UPDATE users set ip_last = '".$_SERVER['REMOTE_ADDR']."', online='1', disconnect ='0' where username = '".mysql_real_escape_string($_POST["username"])."'");				
			}else{
				$empty_fields['error'] = "<div style=\"background: #c0392b; text-align: center; padding: 10px; border: 1px solid #2c3e50; box-shadow: 0 0 5px #2c3e50;\"><font color=\"white\">Deine Logindaten sind falsch.</font></div>";
			}
		}
	}