Division by zero

I am trying t get the percent of votes form the table poll, but keep getting Division by zero for the line commented below. <snip> if ($res) { echo "bla bla bla"; $sql = "SELECT question, responce1, responce2, responce3, vote1, vote2, vote3, date FROM poll WHERE id = {$_POST['id']}";

    $res = $db->query($sql);
    if (DB::isError($res)) {
        die ($res->getMessage());
    }

while ($row = $res->fetchRow());

	      $id = $row[0];
         $question  = $row[1];
         $responce1 = $row[2];

$responce2 = $row[3]; $responce3 = $row[4]; $vote1 = $row[5]; $vote2 = $row[6]; $vote3 = $row[7]; $date = $row[8]; /* Count the votes*/ $total = $vote1 + $vote2 + $vote3; /* Caluclate */ $perc_vote1 = round(($vote1/$total)*100,2); /* Division by zero*/ $perc_vote2 = round(($vote2/$total)*100,2); /* Division by zero*/ $perc_vote3 = round(($vote3/$total)*100,2); /* Division by zero*/ <snip> TIA Gary