to clear : ( ! ) Notice: Trying to get property of non-object error

 Code:

 function getClientName($clientId){   
        $sql_client = sprintf("SELECT `clientname` FROM `client` WHERE `id`='%s'",$clientId);
        $res_client = mysql_query($sql_client)or die("Query failed ".mysql_error());       
 $clientName = mysql_fetch_object($res_client);
        return $clientName->clientname;
            }

 Error Code:
( ! ) Notice: Trying to get property of non-object in   return $clientName->clientname;

Solved Code :

function getClientName($clientId){  
        $sql_client = sprintf("SELECT `clientname` FROM `client` WHERE `id`='%s'",$clientId);
        $res_client = mysql_query($sql_client)or die("Query failed ".mysql_error());      
 $clientName = mysql_fetch_object($res_client);
             
  if($clientName){
            return $clientName->clientname;
                    }
                    else{
                        return null;
                    }
    }