<?php
session_start();
echo 'Welcome to private message system!';
echo '<form method="POST">
Username:
<input type="text" name="Username">
<br>Password:
<input type="password" name="pass">
<br><input type="submit" name="goo" value="Login">
</form>';
mysql_connect('host', 'user', 'pass');
mysql_select_db('Oh, this is tralala');
if ($_POST['goo']== 'Login') {
    $username=$_POST['Username'];
    $password=$_POST['pass'];
    $query="SELECT * FROM Users WHERE Username=\"$username\" AND Password=\"$password\"";
    $q = mysql_query($query);
    if ($q == true) {
        while ($row = mysql_fetch_assoc($query)) {
            str_replace('||', '<br>', $row['Messages']);
            echo $row['Messages'];
        }
        $_SESSION['isLogged'] == true;
        $_SESSION['Username'] = $_POST['username'];
        echo '<br><a href="privatemessage.php?send=true">Send a message</a>';
    } elseif ($query == false) {
        echo 'Wrong username or passsword!';
    }
}

if ($_SESSION['isLogged'] == true && $_GET['send'] == true) {
    echo '<form method="POST">
Username to send to:
<input type="text" name="usernametosend">
<textarea rows="10" cols="20" name="Message">
Enter your message text here :)
</textarea>
<input type="submit" name="goez123" value="Send">';
    if ($_POST['goez123']== 'Send') {
        $msgfrom = $_SESSION['username'];
        $msgseperator = '||';
        $uns=$_POST['usernametosend'];
        $oldstuff="SELECT * FROM Users WHERE Username=\"$uns\"";
        $oldq = mysql_query($oldstuff);
        $oldmsg = mysql_fetch_assos($oldq);
        $msgcontent = 'From: ' . $msgfrom . $oldmsg['privatemssages'] . $msgseperator . $_POST['Message'];
        $newq="UPDATE SET privatemessages = \"$msgcontent\" WHERE Username=\"$uns\"";
        mysql_query($newq);
        echo 'Friend Added :)';
    }
}
?>