{
    print "Enter a number 0-9\n";
    $number=<STDIN>;
    chomp($number);
    unless(length($number) == 1  && $number =~ /[0-9]/){
        print "C'mon, man! give me a number 0-9!\n";  
        redo;  
    }
} 

##</code><code>##

GET_NUMBER:{
    print "Enter a number 0-9\n";
    $number=<STDIN>;
    chomp($number);
    unless(length($number) == 1  && $number =~ /[0-9]/){
        print "C'mon, man! give me a number 0-9!\n";  
        redo GET_NUMBER;  
    }
} 

##</code><code>##

my $number;  

PROMPT_FOR_NUMBER:{
        print "Enter a number 0-9\n";
        GET_NUMBER:{
            $number=<STDIN>;
            chomp($number);
            unless(length($number) ==1  && $number =~ /[0-9]/){
                print "You don't want to give me one number ?\n";  
                redo PROMPT_FOR_NUMBER;
            }
        } 
}