Sending multiple parameters to AutoComplete extender in asp.net using web method

hi guys.. i'm able to show returned result to AutoCompleteExtender by referring the following URL:

https://www.aspsnippets.com/Articles/AJAX-AutoCompleteExtender-Example-in-ASPNet.aspx

I wondering how can i pass one more value to WebService instead of only prefixText + Count

Please advise. TQ