my @teacher_input = $mech->find_all_inputs( { 
                                              type     => 'option',
					      name     => 'teacher',
					    }
                                         );


Reference found where even-sized list expected at /usr/local/share/perl/5.10.0/WWW/Mechanize.pm line 973.
 at /usr/local/share/perl/5.10.0/WWW/Mechanize.pm line 973