eBay SOAP webapp Error : SimpleDeserializer encountered a child element..?

[Emm]

I'm new to ebay API and I'm trying to create a webapp with PHP and eBay trading API but it's not working ... I'm getting this error :\[quote\] 20170 : Schema XML request error. Schema XML request error: SimpleDeserializer encountered a child element, which is NOT expected, in something it was trying to deserialize..\[/quote\]with this call\[code\]<?xml version="1.0" encoding="utf-8" ?><CompleteSaleCall xmlns="urn:ebay:apis:eBLBaseComponents"> <RequesterCredentials> <eBayAuthToken>ABC</eBayAuthToken> </RequesterCredentials><Shipment> ShipmentType <ShipmentTrackingDetails> ShipmentTrackingDetailsType <ShipmentTrackingNumber>ShipmentTrackingNumber</ShipmentTrackingNumber> <ShippingCarrierUsed>UPS</ShippingCarrierUsed> </ShipmentTrackingDetails> </Shipment> <Shipped>true</Shipped> <TransactionID>564548764546</TransactionID> <WarningLevel>High</WarningLevel> <ItemID>123456456</ItemID></CompleteSaleCall>\[/code\]Anyone knows how to make it work ?