Redirect after form submission - php

Question

I'm using the Mingle plugin for Wordpress for users to register, so they can post on a Mingle Forum.
The signup process works, but I want to redirect the user to the forum page once they have submitted their details, rather than just staying on the signup page.
I've tried adding <input type="hidden" name="redirect_to" value="<?php echo bloginfo('url'); ?>" /> to the code so that the page redirects (as it worked on the login form), but doesn't seem to work with signup form.
I've tried using the "action" function in the form details too; this redirects the page, but doesn't submit the data.
The page's code is below - would really appreciate a solution, if possible! Thanks.
<form name="registerform" id="registerform" method="post">
<input type="hidden" id="mngl-process-form" name="mngl-process-form" value="Y" />
<input type="hidden" name="redirect_to" value="http://creativespotlights.com/forum" action="http://creativespotlights.com/forum" />
<p>
<label><?php _e('Username', 'mingle'); ?>*:<br />
<input type="text" name="user_login" id="user_login" class="input mngl_signup_input" value="<?php echo $user_login; ?>" size="20" tabindex="200" /></label>
</p>
<p>
<label><?php _e('E-mail', 'mingle'); ?>*:<br />
<input type="text" name="user_email" id="user_email" class="input mngl_signup_input" value="<?php echo $user_email; ?>" size="25" tabindex="300" /></label>
</p>
<?php if(isset($mngl_options->field_visibilities['signup_page']['name'])) { ?>
<p>
<label><?php _e('First Name', 'mingle'); ?>:<br />
<input type="text" name="user_first_name" id="user_first_name" class="input mngl_signup_input" value="<?php echo $user_first_name; ?>" size="20" tabindex="400" /></label>
</p>
<p>
<label><?php _e('Last Name', 'mingle'); ?>:<br />
<input type="text" name="user_last_name" id="user_last_name" class="input mngl_signup_input" value="<?php echo $user_last_name; ?>" size="20" tabindex="500" /></label>
</p>
<?php } ?>
<?php if(isset($mngl_options->field_visibilities['signup_page']['url'])) { ?>
<p>
<label><?php _e('Website', 'mingle'); ?>:<br />
<input type="text" name="mngl_user_url" id="mngl_user_url" value="<?php echo $mngl_user_url; ?>" class="input mngl_signup_input" size="20" tabindex="600"/></label>
</p>
<?php } ?>
<?php if(isset($mngl_options->field_visibilities['signup_page']['location'])) { ?>
<p>
<label><?php _e('Location', 'mingle'); ?>:<br />
<input type="text" name="mngl_user_location" id="mngl_user_location" value="<?php echo $mngl_user_location; ?>" class="input mngl_signup_input" size="20" tabindex="700" /></label>
</p>
<?php } ?>
<?php if(isset($mngl_options->field_visibilities['signup_page']['bio'])) { ?>
<p>
<label><?php _e('Bio', 'mingle'); ?>:<br />
<textarea name="mngl_user_bio" id="mngl_user_bio" class="input mngl-growable mngl_signup_input" tabindex="800"><?php echo wptexturize($mngl_user_bio); ?></textarea></label>
</p>
<?php } ?>
<?php if(isset($mngl_options->field_visibilities['signup_page']['sex'])) { ?>
<p>
<label><?php _e('Gender', 'mingle'); ?>*: <?php echo MnglProfileHelper::sex_dropdown('mngl_user_sex', $mngl_user_sex, '', 900); ?></label>
</p>
<?php } ?>
<?php if(isset($mngl_options->field_visibilities['signup_page']['password'])) { ?>
<p>
<label><?php _e('Password', 'mingle'); ?>:<br/>
<input type="password" name="mngl_user_password" id="mngl_user_password" class="input mngl_signup_input" tabindex="1000"/></label>
</p>
<p>
<label><?php _e('Password Confirmation', 'mingle'); ?>:<br />
<input type="password" name="mngl_user_password_confirm" id="mngl_user_password_confirm" class="input mngl_signup_input" tabindex="1100"/></label>
</p>
<?php } else { ?>
<p id="reg_passmail"><?php _e('A password will be e-mailed to you.', 'mingle'); ?></p>
<?php } ?>
<?php if($mngl_options->signup_captcha) { ?>
<?php
$captcha_code = MnglUtils::str_encrypt(MnglUtils::generate_random_code(6));
?>
<p>
<label><?php _e('Enter Captcha Text', 'mingle'); ?>*:<br />
<img src="<?php echo MNGL_SCRIPT_URL; ?>&controller=captcha&action=display&width=120&height=40&code=<?php echo $captcha_code; ?>" /><br/>
<input id="security_code" name="security_code" style="width:120px" type="text" tabindex="1200" />
<input type="hidden" name="security_check" value="<?php echo $captcha_code; ?>">
</p>
<?php } ?>
<?php do_action('mngl-user-signup-fields'); ?>
<br class="clear" />
<p class="submit"><input type="submit" name="wp-submit" id="wp-submit" class="mngl-share-button" value="<?php _e('Sign Up', 'mingle'); ?>" tabindex="60" />
</p>
</form>

Answer 1

Try this
<?php
if (isset($_POST['wp-submit']))
{
header('Location: http://site/result.php');
}
?>
in the top of your code
OR you can try to do it by javascript with onsubmit="window.location.href='result.php';"

Answer 2

You can use :
header('Location: http://yoursite.com/location.php');
But you have to get a clean output (no html before the header).
Doc here.

Answer 3

Something like this should work:
if (isset($_POST['user_login']))
{
(your redirect code here)
}

Answer 4

After a form has been successfully submitted you should perform a 303 redirect to the same page. Doing this will prevent resubmitting the form if the user happens to press F5 or some other form or reloading the page.
wp_redirect("/path/to/my/script", 303);
You will need to substitute /path/to/my/script with the URL where your form lives.