Marc,
Not a problem! I was glad to help. :-)
I don’t know why your Server-Side code is not functioning. I created a sample using the steps I supplied and on my instance it worked fine. The only way I was able to reproduce the error you described was if the “javascript” portion of the URL was not removed. I am glad that at least you got it working on the Client-Side.
There is unfortunately absolutely no way to prevent the PostBack after closing a PopUp. It’s the behavior of the DNN Core PopUp method. Nature of the beast, so-to-speak. You have a few options if you want your original page to reload data it had at the time of PopUp:
1) If working w/ single record, trying passing the RecordID to PopUp and back using QueryStrings. Of course you have to reload the record on the original page again on PageLoad.
2) You can try storing the information temporarily in Cache.
3) You can try storing the information in Session variables (although I do not recommend this option if there is a chance your module will be used in a Server Farm environment)
It was hard for me too when I first started developing for DNN. There isn’t a good “one stop shop” location to find reference information. But, the Resources Menu on the DotNetNuke website is useful, as is this forum. I found it helpful at times to also have a copy of the Community Source code, so you can look up how certain things are done, or if you need to understand how a method functions. There is a DNN6 API Documentation website at (http://dotnetnukeru.com/Dnn6Docs/api/...), but it’s only helpful if you know what you are looking for, more of a reference guide than anything else.
HTH!
-Ben