Pokécheck Shoutbox Historian

#!/bin/bash
sbhistory=$1
if [ $sbhistory -eq $sbhistory 2> /dev/null ]; then
 if [ $sbhistory -gt 5000 ]; then
  echo -e "I can't search a shoutbox history over 5000."
 elif [ $sbhistory -lt 1 ]; then
  echo -e "I can't search a non-positive shoutbox history."
 else
  # eventually we will give the user a choice of browser here
  string="firefox -new-tab http://www.pokecheck.org/shoutbox.php?history=${sbhistory}"
  $string
 fi
else
echo -e "You gave me something besides a number."
fi