Undefined index error - help please

ukphp

Hi,

I appear to be getting an Undefined index: username in C:\wamp\www\blog\login.php on line 13. Any idea how to fix this?

<?php
mysql_connect("localhost", "root", "");
mysql_select_db("blog");
?>

<html>
    <head>
        <title>Login</title>
    </head>
    <body>
        <?php
        if (isset($_POST['submit'])) {
            $user = mysql_real_escape_string ($_POST['username']);    // line 13
            $pass = mysql_real_escape_string ($_POST['password']);

        $result = mysql_query("SELECT * FROM users WHERE username='$user' AND password='$pass' ");
        $num = mysql_num_rows($result) or die($result."<br/>".mysql_error());;
        echo $num;

        } else {
        echo "Please enter your details.";
    }
    ?>

    <form action="login.php" method="POST">
        Username: <input type="text" name="username" /><br />
        Password: <input type="password" name="password" />
        <input type="submit" name="submit" value="Login" />
    </form>
</body>
</html>

Weedpacket

Like every other variable coming from a form, check that [font=monospace]$POST['username'][/font] (and [font=monospace]$POST['password'][/font]) actually exist before trying to use them. (And have some idea of what you want to do if they don't.)

Also, read the warnings at the top of the [man]mysql_connect[/man], [man]mysql_select_db[/man], [man]mysql_real_escape_string[/man], [man]mysql_query[/man], and [man]mysql_num_rows[/man] pages.