여러번 올렸는데 답이 없네요.

function getTotal($wr_id, $select, $stay)
{
global $g4, $board;
$result = 0;
$write = sql_fetch("SELECT * FROM {$g4['write_prefix']}{$board['bo_1']} WHERE wr_id = '{$wr_id}'");
for($i = 0; $i < $stay; $i++)
{
list($date) = mysql_fetch_array(sql_query("SELECT '{$select}' + INTERVAL {$i} DAY"));
$field = getPrice($date);
$result += $write[$field];
}
return $result;
}

function checkTotal()
{
var total = 0;
var result = 0;
var form = document.getElementById("write");
var max = form.length;
for(var i = 0; i < max; i++)
{
if(form.elements[i].name == "room[]" && form.elements[i].checked == true)
{
var wr_id = form.elements[i].value;
var price = document.getElementById("price[" + wr_id + "]").innerHTML.replace(/,/g, "");
total += parseInt(price);
result++;
}
}
document.getElementById("total").innerHTML = getComma(total);
return result;
}

여기에서 2일째부터 discount 요금 적용시킬려고 합니다
어떻게 하면 되나요..