The eLandings system incorporates several stand-alone applications for data entry, modification, and review. These front end applications include the eLandings web pages, sealandings and tlandings. These systems all communicate with the database in the same fashion via web services. Arbitrarily, we will use the test eLandings web pages in our examples to explain web service calls in this document.
The eLandings web page is located at:
Test:
Training:
Production:
All elandings applications communicate with the eLandings database through web services. All data sent between the web services and web service clients is communicated as Strings in XML format. 
The XML is defined by XSD available for download. The XSD files have a Schema version associated with it. eLandings is actively under development. New elements are regularly added to the XML structures. When the XML structures change, the XSD file gets an incremented schema number. eLandings looks at the schema version number each time a XML string is converted into a Data object or a Data object is converted into a XML string. eLandings has some logic to convert an older versions of the XML to the current version and vice versa in the web services. This allows older versions of eLandings applications to continue to communicate with the webservices inspite of new structure changes. This is not always possible or practical. In these cases, eLandings will not be able to process the XML, an error could be returned, or data could be lost.