I knew that ideal solution is in really effective talk between Client and Server.
So my criterias were:
1) No DUBLICATES of data transferred to Client and Server
2) Its must be fully CROSSBROWSER (some of my users work on Mac)
3) Very simple to INTEGRATE with existing applications, that means NO CHANGES to code, NO SPECIAL helper classes that make for example Scripts. Everything like in usually ASP.NET application.
5) It must support .NET 1.1 and .NET 2.0 and maybe Mono or other Servers (like Apache)
6) Working with ANY COMPLEX Server Controls
So it must be easy to create application as though you not afraid some superfluous PostBacks, but that helps you to make site very quickly. Solution was founded FastPage!