global $base_url;
l("Member Login", $base_url."/user/login?".drupal_get_destination()),);

When adding a link to a form say for instance a login form you can use drupal_get_destination() to return the user to the page they were on when they finish loging in. This show you how to do this programatically in a link l(); function.

Using drupal_get_destination() in a link item "l()"

links, drupal

PHP