Login problems

I ran into some problems in the login.
The index page shows this:

<form action="login/login.php" method="post"> 
  <label for="login-username" style="float: left; margin: 0px 0px 0px 5px;">Username:</label><br /> 
  <input type="text" name="username" id="login-username" value="" style="float: left; margin: 0px 0px 0px 5px; border: 1px solid #7A1010; color: #7A1010;" />
  <label for="login-password" style="float: left; margin: 0px 0px 0px 5px;" >Password:</label><br /> 
  <input type="password" name="password" id="login-password" value="" style="float: left; margin: 0px 0px 0px 5px; border: 1px solid #7A1010; color: #7A1010;" /><br /> 
  <br />
  <label for="login-remember" style="float: left; margin: 0px 0px 0px 5px;">Remember me?</label>
  <input type="checkbox" name="remember" id="login-remember" style="float: left; margin: 5px 0px 0px 5px;" /><br />
  <input type="submit" value="Login" style="float: left; margin: 0px 0px 0px 5px; background-color: #7A1010; color: #EAE8C8;" />
</form> 

The form leads to here:

<?php
// Database connection file
require_once("includefiles/dbconnection.php");
$un=isset($_POST['username']) ? $_POST['username'] : "";
$pw=isset($_POST['password']) ? $_POST['password'] : "";
echo "Hellooooooo!!!!!!!!!!!!".$un." ".$pw;
// Form submitted?
if($_SERVER['REQUEST_METHOD'] == "POST"){
	$errors = array();
	// Validate form
	foreach($_POST as $key => $value){
		if(empty($value)){
			$errors[$key] = $key . " was empty";
		}
	}
	// If no errors, continue
	if(count($errors) == 0){
		$sql = sprintf("SELECT usergroup AS success FROM {$dbTable} WHERE username='%s' AND password=MD5('%s')", $un, $pw; extract(mysql_fetch_assoc(mysql_query($sql)));
		//echo $sql;
		// If this is not set, there was an error
		if(!isset($success)){
			$errors[] = "that username and password combination are incorrect";
		}else{
			// Remember me?
			if(isset($_POST['remember'])){
				setcookie("login", $_POST['username'] . ":" . $success, time() + (3600 * 24 * 30)); // store for 30 days
			}
			// Log the user in
			$_SESSION['login'] = true;
			$_SESSION['username'] = $_POST['username'];
			$_SESSION['group'] = $success;
			$_SESSION['just_logged_in'] = true; // to display a message
			// Redirect back to the main page
			$redirect = true;
			unset($errors);
		}
	}
}else{
	// The form was not submitted, so they shouldn't be here
	$redirect = true;
}
// Redirect if needed
if(isset($redirect)){
	header("Location: " . $baseURL);
	exit;
}
include("login-form.php");
?>

But this page shows blank.

You need to enable error displays. You have just run into a WPSE (White Page of Syntax Error)

I get errors on this line.
$sql = sprintf(“SELECT usergroup AS success FROM {$dbTable} WHERE username=‘%s’ AND password=MD5(‘%s’)”, $un, $pw; extract(mysql_fetch_assoc(mysql_query($sql)));

(Which… really should be two lines, btw)

Ok the actual should be:

      $sql = sprintf("SELECT usergroup AS success FROM {$dbTable} WHERE username='%s' AND password=MD5('%s')"
                   , mysql_real_escape_string($_POST['username']), $_POST['password']);
      extract(mysql_fetch_assoc(mysql_query($sql)));
      echo $sql;

I still haven’t received an answer.

enable error displays:


ini_set('display_errors',1);
error_reporting(E_ALL);

and see if it gives you an actual error; your script includes files that I cannot see (dbconnection.php and login-form.php) that may be throwing errors.