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.
Probably the best way to do this would be to use AJAX. Since you're already using JavaScript, it would be a simple matter of adding the service call at the finalization stage of the action to implement the database changes directly.

<http://msdn.microsoft.com/en-us/library/aa479042.aspx>