Having an add_action( 'user_new_form',)

I am using the following action;

add_action( 'user_new_form', 'epx_add_user_form_to_admin_area',489);
function epx_add_user_form_to_admin_area($current){
   $current .= 'this is a test';
   echo $current;
}

The issue is the minute i put that in s2member which displays a load of options on the add user page in the admin not to display

^^That is when i have not got anything that whats s2 member shows

^^That is when i use the code above.

It is like it is overwritten what s2member wants to display. What is the best way to output new themes without removing s2member items which are required!

Many Thanks for any help.