Validation and pop-up in custom MWS portlet

Dear wmusers,

I am developing custom portlet in MWS, which should work as an input form - user fills some data in, submits it and as a result, document is published on Broker (document starts business process afterwards).

However, I am still failing accomplish 2 features using CAF portlet development:

  1. I want to trigger validation on some form fields on form submit. Currently, if I turn on validation, it is being triggered on each postback (there are some hierarchical dropdown boxes which can cause this during form filling).
  2. After submit, I need user to be informed, that submit suceeded (display message as a result of a service on IS). I want to do this via pop-up, but dunno how to run server-side service before triggering client-side po-up automatically.

I’m new to wM, same as have no experience with JSP - sorry if my questions will be too basic:)