Save multiple values in multiple HiddenField on jQuery AutoComplete selection using C# and Ajax in ASP.Net

Hello,

I am not at all familiar with jQuery, but I came across this (https://www.aspsnippets.com/Articles/Implement-jQuery-AutoComplete-TextBox-from-database-using-AJAX-PageMethods-in-ASPNet.aspx)and I implimented it in a project of mine where I am trying to create a pdf with data taken from an Access database, corresponding to a certain user input.

My question is how can i insert additional hidden fields so that I can retrieve additional data from the database and use it accordingly.

Please, I would apreciate a more elaborate answer since as I mentioned above I am not at all familiar with jQuery and AJAX.