The GUI will need to be pretty rich. The web app will be pretty hefty, as will the information that we need to push across it and persist between posts.

Right now, our strategy will probably be to pull all the data the client is likely to need for the DB but use DHTML to only display what they need to see so that the user can navigate through tree structures to see the info that they need. Any real processing will happen server-side. We want to push as much validation onto the client as we can and, as much as possible, handle all hide/show display issues there.

I have been looking at Client Callbacks, which are coming in ASP.NET 2.0. There is a nice introduction at http://fredrik.nsquared2.com/viewpost.aspx?PostID=113 that clearly walks through the simple sample code. I don't think that we will want to consider remote scripting. The only possible advantage to using remote scripting would seem to be broader browser support.

I don't think that we would want to do a browser plug-in because of the problems with code maintenance. We have complex business rules that change pretty frequently and making end-users download a lot of plug-in updates would undermine a lot of the benefits of a web app.

I should probably research the validation controls available for ASP.NET. I have a VS.NET 2.0 beta 2 DVD. I just need to explore it at home so it won't cause problems for my copy of VS.NET 1.1 at work.

>Everything depend what will be the requirements for the application.
>Will be there requirements for rich GUI or some special validations or processing.
>Before to create detailed description of the Navigation, UI, etc. It will be difficult to receive any good advice.
>Last year we have made N-tier application for Cheques printing. And in the end appears that printing in web version could be done through browser, only if we use custom C# plug-in.
>HTH