I've tried: 
$start = $ARGV[0];

if ($start eq '') {
    $start = &get_start_level;
}
sub get_start_level {
    print "Please Enter the Start-Level (0-7,?)[0]: ";    
    $input = <>;
    # clear all but numbers or '?'
    #if ($input ne '?') {
    #    $input =~ tr/!(0-9)//\d;
    #}
    
    if ($input eq '?') {
      print " **** internally coded help information  **** \n";
    print " **** internally coded help information  **** \n";
    $input = &get_start_level;
    } elsif (($input < 0) || ($input > 7)) {
    print "please enter a number that is between Zero and Seven\n";
    $input = &get_start_level; 
    }
    return ($input);
}
  =========================== end code  ============

[download]
This seems to me like a pretty straight forward problem. What am i doing wrong? ... I can't seem to figure this out.

Originally posted as a Categorized Question.

In reply to How can I validate user input? by Buckaroo Buddha

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