From Xojo Documentation
Returns the query part of the requested url. Using the URL http://mydomain.com/folder/file?query as an example, this property would be set to "query".
This code in WebApplication.HandleURL could fetch information about a user in the database and return it as XML:
Var id As String = Request.QueryString
If id <> "" Then
// Create XML containing data for the user ID
Var xml As String
xml = CreateUserXML(id)