$fetch_users_data = mysql_fetch_object(mysql_query("SELECT * FROM `members` WHERE username='".$_SESSION['username']."'"));

This is a code from user login php template. It shows error in this code. Can you find it.
here is the full screenshot of errors.

postimage.org/image/59c5tjgrt/

First error is of this code.
Which is
undefine variable _session