if ($entry >=5) {my $backnum= $entry-5} else {my $backnum=0};
my $nextnum=$entry+5;
while ($entry % 5) {
#do your output stuff ;
$entry++;
  if ($backnum) {
                   print "<a href=\"myscript.cgi?$backnum\">Previous</a>"};
};

print "<a href=\"myscript.cgi?$nextnum\">Next</a>"};
#other stuff...