There are several good examples on blogs and the ServiceNow wiki of creating a popup-style dialog box to show form or list data from another ServiceNow form. I wanted to use those examples to create yet another scenario: From a ServiceNow list, right-click on a record and have an external website pop up as a dialog box and accept information from the list record that was selected.
In this example, users can browse incidents in their ServiceNow instance. In the list view, they can right-click an incident and choose an option to view related search results in Mozilla's Open Directory Project (DMOZ.org). The action will take the terms from the "Short Description" field on the selected incident and show search results on those terms from DMOZ.
To read more about how to set this up in your own instance read more at Pass form data to a Popup Dialog Window.
