Amazon MWS Marking order as shipped

I have listed all of my Amazon orders to my site.
Now, i want to have ability to mark order as shipped from my site and the status will be instantly updated on amazon.
I have looked at amazon feed api but not clear about the format of feed xml.

I just want an example feed xml for updating order status.
( actually i want to know which parameters in xml feed should i send to mark order status as shipped.)

Solution

If you search for Ship and Confirm Shipment (and get paid) - Order Fulfillment on Seller Central it will bring you to a page that provides the XSD and a sample XML file for this feed.

The XML is provided below per your request:

<?xml version="1.0" encoding="UTF-8"?>
<AmazonEnvelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="amzn-envelope.xsd">
    <Header>
        <DocumentVersion>1.01</DocumentVersion>
        <MerchantIdentifier>My Store</MerchantIdentifier>
    </Header>
    <MessageType>OrderFulfillment</MessageType>
    <Message>
        <MessageID>1</MessageID>
        <OrderFulfillment>
           <MerchantOrderID>1234567</MerchantOrderID>
           <MerchantFulfillmentID>1234567</MerchantFulfillmentID>
           <FulfillmentDate>2002-05-01T15:36:33-08:00</FulfillmentDate>
           <FulfillmentData>
               <CarrierCode>UPS</CarrierCode>
               <ShippingMethod>Second Day</ShippingMethod>
               <ShipperTrackingNumber>1234567890</ShipperTrackingNumber>
           </FulfillmentData>
            <Item>
               <MerchantOrderItemID>1234567</MerchantOrderItemID>
               <MerchantFulfillmentItemID>1234567</MerchantFulfillmentItemID>
               <Quantity>2</Quantity>
           </Item>
        </OrderFulfillment>
    </Message>
</AmazonEnvelope>

From the documentation:

Once you've shipped the order, send Amazon a shipping confirmation with fulfillment information