Export order number instead of invoice number

Question

I got this code:

public function loadInvoice($invoiceno) 

  if ($invoiceno instanceof Mage_Sales_Model_Order_Invoice) {
    $invoice = $invoiceno;
  }
  else {
    $invoice = Mage::getModel('sales/order_invoice')->loadByIncrementId($invoiceno);
  }

  $ordernumber = 0;
  $invoice_collection = $invoice->getOrder()->getInvoiceCollection()->getItems();
  if (count($invoice_collection) > 1) {
    $count = 0;
    foreach ($invoice_collection as $key => $value) {
      $count++;
      if ($value->getIncrementId() == $invoice->getIncrementId()) {
        if ($count == 1) {
          $ordernumber = $invoice->getOrder()->getIncrementId();
        }
        else {
          $ordernumber = $invoice->getOrder()->getIncrementId().'_'.$count;
        }
        break;
      }
    }
  }

  if (!$ordernumber) {
    $ordernumber = $invoice->getOrder()->getIncrementId();
  }

And I want to export the order number, instead of the invoice number.

Answer 1

Answer is to change invoice_collection to order.

Then it will export right.