I already answered your support ticket, but I will also post here so other people can benefit from the information as well:
The demo page that Tervel linked to includes one XmlHttpPanel, which calls a web service. The parameter for the web service is set in the panel's Value property - either on the client - panel.set_value("test")
- or on the server - panel.Value = "test"
. You can pass the user information in the value and read it on the server in the web method. The code for this in the linked example is in our demo application - the ~\App_Code\ToolTipWebService.cs file and the GetCustomersByCountryXmlHttpPanel() method.
the Telerik team