Not able to debug an XSD

[Aq1]

Here is my XSD. I am not able to understand why I keep getting this error:\[quote\] CDIER0202E: Internal Fatal DOM error encountered while loading XML schema=:urn|library|Test123247_1|resource|SmallCase.xsd:urn|library|Test123247_1|resource|SmallCase.xsd:urn|library|Test123247_1|resource|SmallCase.xsd:3:35:322:The prefix "xsd" for element "xsd:element" is not bound..\[/quote\]Here is the new XSD after edits:\[code\]<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:scotiaXML="http://xml.scotia.com" targetNamespace="http://xml.scotia.com" elementFormDefault="qualified" attributeFormDefault="unqualified" version="1.0"><!-- Begin Level 1 =============================================--><xsd:element name="OTC_Matching" type="temp"/><xsd:complexType name="temp" mixed="false"> <xsd:sequence> <xsd:choice> <xsd:element ref="PostTrade"/> </xsd:choice> </xsd:sequence></xsd:complexType><!-- End Level 1 =============================================--><xsd:element name="PostTrade" type="PostTradeTransaction"/><xsd:complexType name="PostTradeTransaction" abstract="true"> <xsd:sequence> <xsd:choice> <xsd:element name="elem1" type="xsd:string"/> </xsd:choice> </xsd:sequence></xsd:complexType>\[/code\]