Question: I have a table and rows are added by users by clicking in a button. I do this with Javascript.
But then I have to get the values with C# and add then to database. C# is mandatory.
How can I do this?

Answer: 
Use [`AJAX`](http://en.wikipedia.org/wiki/Ajax_%28programming%29) to get/send the values from and to the server.
you can do it by using jquery & ajax
if you dont want you can put all new values in new rows in a hidden field (with a proper structure) and read hidden field value in server side