help with validation existense of two or more fields

hi all,
i have registration script that registers user according their user ID. if there more than one user id it returns false and says that this user ID is taken. but if i submit different user ID and the same email address it accepts. how can i do that if both user id and email exists it says that the user id is taken and the email is taken. thanks for attention
here is script

<?php
	//Start session
	session_start();
 include("config/connect.php");
	    
	    $az=new funksiyalar('karyeram');

	
	//Array to store validation errors
	$errmsg_arr = array();
	
	//Validation error flag
	$errflag = false;
	
	//Connect to mysql server
	
	
	//Function to sanitize values received from the form. Prevents SQL injection
	function clean($str) {
		$str = @trim($str);
		if(get_magic_quotes_gpc()) {
			$str = stripslashes($str);
		}
		return mysql_real_escape_string($str);
	}
	
	//Sanitize the POST values
	$fname = clean($_POST['fname']);
	$lname = clean($_POST['lname']);
	$login = clean($_POST['login']);
	$password = clean($_POST['password']);
	$email = clean($_POST['email']);
	$cpassword = clean($_POST['cpassword']);
	
	//Input Validations
	if($fname == '') {
		$errmsg_arr[] = 'Name necessary';
		$errflag = true;
	}
	if($lname == '') {
		$errmsg_arr[] = 'Surname is required';
		$errflag = true;
	}
	if($login == '') {
		$errmsg_arr[] = 'Login is required';
		$errflag = true;
	}
	if($password == '') {
		$errmsg_arr[] = 'Password is required';
		$errflag = true;
	}
	if($cpassword == '') {
		$errmsg_arr[] = 'please repeat password';
		$errflag = true;
	}
	if( strcmp($password, $cpassword) != 0 ) {
		$errmsg_arr[] = 'Passwords dont match';
		$errflag = true;
	}
	
	//Check for duplicate login ID
	if($login != '') {
		$qry = "SELECT * FROM members WHERE login='$login'";
				$result = mysql_query($qry);
		//$yeni=mysql_fetch_array($result);
		//$yeni[]
		
		if($result) {
			if(mysql_num_rows($result) > 0) {
				$errmsg_arr[] = 'This login is already taken';
				$errflag = true;
			}
			@mysql_free_result($result);
		
		
				}
		else {
			die("Query failed");
		}
		}
	
	//If there are input validations, redirect back to the registration form
	if($errflag) {
		$_SESSION['ERRMSG_ARR'] = $errmsg_arr;
		session_write_close();
		header("location: register-form.php");
		exit();
	}

	//Create INSERT query
	$qry = "INSERT INTO members(firstname, lastname, login, passwd, password, email) VALUES ('$fname','$lname','$login','".md5($_POST['password'])."','$password','$email')";
	$result = @mysql_query($qry);
	
	//Check whether the query was successful or not
	if($result) {
		header("location: register-success.php");
		exit();
	}else {
		die("Query failed");
	}
?>

Thanks for attention in advance