I'm calling web service List.asmx using Jquery and getting results using this but its not ordering by DisplayOrder. This is the caml query.
<soapenv:Envelope xmlns:soapenv='http://schemas.xmlsoap.org/soap/envelope/'> \
<soapenv:Body> \
<GetListItems xmlns='http://schemas.microsoft.com/sharepoint/soap/'> \
<listName>Master-Footer-Links</listName> \
<viewFields> \
<ViewFields> \
<FieldRef Name='Title' /> \
<FieldRef Name='DisplayOrder' /> \
<FieldRef Name='Url' /> \
</ViewFields> \
</viewFields> \
<Query> \
<OrderBy><FieldRef Name='DisplayOrder' Ascending='TRUE' /></OrderBy> \
</Query> \
</GetListItems> \
</soapenv:Body> \
</soapenv:Envelope>