I love questions =)

[Hall of Famer]

Well find these lines in your levelup.php:

PHP Code:

    if($isfrozen == "no"){   
    changecash(grabanysetting('rewardmoney'), $GLOBALS['username'], $GLOBALS['money']);
    $article_content = $article_content . "<div align='center'><br />You have earned ". grabanysetting('rewardmoney') ." ". grabanysetting('cost') ." for leveling up this adoptable. <br />You now have {$GLOBALS['money']} ".grabanysetting('cost')."</div>";
    } 


Replace with:(assuming the maximum level on your site is 5, as inferred from your script)

PHP Code:

    if($isfrozen == "no" and $currentlevel <5){   
    changecash(grabanysetting('rewardmoney'), $GLOBALS['username'], $GLOBALS['money']);
    $article_content = $article_content . "<div  align='center'><br />You have earned ".  grabanysetting('rewardmoney') ." ". grabanysetting('cost') ." for  leveling up this adoptable. <br />You now have {$GLOBALS['money']}  ".grabanysetting('cost')."</div>";
    } 


Give a try on your site and see if it works.

Hall of Famer