gt (see Relational Operators in perlop) is a string (lexicographic/asciibetic) comparison, and '100000' or even '1000000000' is lexicographically less than '99999' or even '9'. Use a numeric comparison: 

c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = '99999';
 print qq{A: '$s'};
 ;;
 $s++;
 print qq{B: '$s'};
 ;;
 $s = '00001' if $s > 99999;
 print qq{C: '$s'};
"
A: '99999'
B: '100000'
C: '00001'

[download]

Update: Oops... See Athanasius below. But this works: 

c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = '01';
 ;;
 for (0 .. 105) {
   print qq{'$s'};
   $s++;
   $s = '01' if do { (my $t = $s) > 99 };
   }
"
'01'
'02'
'03'
'04'
'05'
'06'
...
'97'
'98'
'99'
'01'
'02'
'03'
'04'
'05'
'06'
'07'

[download]

Give a man a fish:  <%-{-{-{-<

In reply to Re^4: POE - can't increment within sub by AnomalousMonk
in thread POE - can't increment within sub by ljamison

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