if ($headerStr)
{ 
   my @headerElements = split /\s+/, $headerStr;
}

##</code><code>##

#!/usr/bin/perl -w

#### NOTE: strict is not in force!! ###
set_a();
print "a outside of sub is $a\n";
print "b outside of sub is $b\n";

sub set_a
{
   $a = int(rand(100));
   print "a in sub is $a\n";
   my $b = int(rand(100));
   print "b in sub is $b\n";
}

__END__
Name "main::b" used only once: possible typo at C:\TEMP\scopedemo.pl line 5.
Use of uninitialized value $b in concatenation (.) or string at C:\TEMP\scopedemo.pl line 5.
a in sub is 27
b in sub is 45
a outside of sub is 27
b outside of sub is 

##</code><code>##

#!/usr/bin/perl -w
use strict;

my $ref = getaref();
print "ref points to $$ref\n";

my $refb = getaref();
print "refb points to $$refb\n";

print "ref still points to $$ref\n";


sub getaref
{
   my $a = int(rand(100));
   print "a in sub is $a\n";
   return (\$a);
}
__END__
a in sub is 89
ref points to 89
a in sub is 28
refb points to 28
ref still points to 89 (the memory for the value of 89 is
                        separate from the memory of the
                        value of 28)