note 58765 added to function.eregi-replace

I have thwe following script to restrict email addresses to those ending in .ac.uk. however, the following does not work rahul@sthildas.ox.ac.uk whereas rahul@ox.ac.uk. (it seems two things after the @ and before the .ac.uk are not accepted. What am I doing wrong? ^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+([\.]ac[\.]uk)+$ ---- Manual Page -- http://www.php.net/manual/en/function.eregi-replace.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+58765 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+58765&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+58765&report=yes Search -- http://master.php.net/manage/user-notes.php