Redirect a user after login to messaging module

Hi All.
Thanks a lot to read my request
i am using Private messaging module what i want is to redirect user to Messaging page after login
for this i am using login destination module
i am trying

user/$user->UID/messages

also tried

echo("user/".$user->UID."/messages");

in php snipped and kept the preservre destination checkbox unchecked

it does not works
i tried
Blog

it worked
please tell me how it can be done i am using drupal 5