Showing url

I have created a web form which has an action button. When I click the action button it executes the agent. If that agent throws error, I would like to popup an error dialog.

  1. Is it possible popup an error dialog?

  2. If not, how can I show the error in the form at the top.

  3. If not, I would like to print the error and an url which user can click to goto proper page.

Thanks,

Kiran