I'm quite new to XSD and I'm stuck on a problem that seemed simple to me ... before I tried.

I would like to write a XSD for the following XML :

```
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<properties>

  <double name="Value1">111.111</double>
  <double name="Value2">222.222</double>

</properties>

```

I want this XSD to be very restrictive, so that Value1 and Value2 are fixed, the only "free" values are 111.111 and 222.222.

*I also would like to force both Value1 and Value2 to be present in the XML file (though not necessarily in that order)*

So I write this XSD :

```
<?xml version = "1.0"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
   <xs:element name="properties">
      <xs:complexType>
         <xs:sequence>
            <xs:element name="double">
               <xs:complexType>
                  <xs:simpleContent>
                     <xs:extension base="xs:decimal">
                        <xs:attribute name="name" type="xs:string" fixed="Value1" use = "required"/>
                     </xs:extension>
                  </xs:simpleContent>
               </xs:complexType>
            </xs:element>
            <xs:element name="double">
               <xs:complexType>
                  <xs:simpleContent>
                     <xs:extension base="xs:decimal">
                        <xs:attribute name="name" type="xs:string" fixed="Value2" use = "required"/>
                     </xs:extension>
                  </xs:simpleContent>
               </xs:complexType>
            </xs:element>
         </xs:sequence>
      </xs:complexType>
   </xs:element>
</xs:schema>

```

Unfortunately, my XML validator gives the following error:

```
Multiple Elements With Name 'double', With Different Types, Appear In The Model Group.

```

I know this kind of issue is known, but I can't find any convenient answer, or simply I don't get them !? Moreover I cannot use XSD 1.1.

Many thanks for any help !