Thank you Jason,
Right the login page is set to redirect this way because the checkout page forces user to login/register before proceeding:
"successRedirect" => "checkout.php?loggedIn=1",
"failRedirect" => "users_login.php?failedLogin=1",
"gotoPreviousURL" => TRUE,
"keepQueryString" => TRUE
as you can see gotoPrevious is also set. This set up goes directly to checkout and this is good so far.
If use the same loging page for the users who are not buying anything how should I go about it with the given set-up.