How can I pass additional data to my WebService?
Extender allows the Web Method that it consumes to provide an optional parameter for passing additional data into it. It’s contextKey. What we need to do is set the ContextKey property of the Extender to desired value, and then this value can be retrieved from the web method via contextKey parameter which should be the last one of the parameter list. Related threads: http://forums.asp.net/t/1130558.