When a user do login successful, he is redirected to the previous page. But, you may want to forward him to the specific URL.
For example, there is the site which allows to login for only administrators. In these case, administrators on login success want to be forwarded to the control panel.
Source code he shown is available as a preload. Copy & Paste, and save as XOOPS_URL/preload/loginRedirect.class.php.