Why won't Express.js properly read POST parameters?

HEre's my POST:

account_id  1231
limit   3
ordertype   limit
quantity    1
symbol  USDJPY
transaction_type    buy

In my code, I have:

 var account_id = req.param('account_id', null);
  var symbol_pair = req.param('symbol', null);
  var transaction_type = req.param('transaction_type', null);
  var order_type = req.param('ordertype', null);
  var amount = req.param('amount', null);
  var limit = req.param('limit', null);

console.log(account_id + " | " + symbol_pair + " | " + transaction_type + " | " + order_type + " | " + amount + " | " + limit);return;

But for some reason ordertype comes back market. Any ideas what's going on?