my @delete_users = param('users');

my %user = map { /^([^\|]*)\|(.*)/ }, <FILE>;
close FILE;

delete %user{@delete_users};

open (FILE, ">$datafile") or die "Can't write: $!";

while(my ($usr,$pwd) = each %user) {
    print FILE "$usr|$pwd\n";
    print "$pwd<br>";
}
close(FILE);