use strict; use warnings; use Switch; my $level1; print "Select options: \n 1 Fiction \n 2 History \n 3 Religion \n"; my $no = getIP('Enter a digit : ', /^\d/); switch ($no) { case 1 { $level1 = ?? } case 2 { $level1 = ?? } case 3 { $level1 = ?? } else { $level1= ?? } } print $level1; sub getIP { print $_[0]; do { $_ = ; chomp; } while ($_[1] && $_ !~ $_[1]); return $_; }