This is a simple yet easy to modify sample of doing a simple HTML modal popup.
I and a couple of my colleagues have been using this example of a modal prompt as quick solution for our every day work. This past week I have seen this show up in 3 different projects. I recently implemented this in 5 minutes and tweaked it as a dynamic content display in about 15 minutes with a custom look. Modal dialogues or prompts are being used more and more by my team to display information, video, prompts and more. Two months ago I used ago I used a variation of this example to show HTML5 video used for training.
View Example: http://ldndeveloper.com/sample/modalprompt/modalprompt.htm
Dowload Example: http://ldndeveloper.com/sample/modalprompt/modalprompt.zip