Making Your Own Cryption in Perl(regular expression)

print "Crypt:";
chomp($crypt=);
my $cr = $crypt;
my $length = length($cr);
for(my $i=0; $i<$length; $i++) {
$ok=substr($cr,$i,1);
&crypt($ok);
}


sub crypt() {
$crypt=shift;
$crypt =~ tr/abcdefghijklmnopqrstuvwxyz/bcdefghijklmnopqrstuvwxy~/;
$crypt =~ tr/ABCDEFGHIJKLMNOPQRSTUVWXYZ/BCDEFGHIJKLMNOPQRSTUVWXY~/;
print $crypt;
}
#of course this code could me made much strange and stranger and better but this is a #basic ;)
#http://tech-bl0od3r.blogspot.com/