You can use the following HTML code to create a popup window within your HTML document. Simply copy, paste, and change the values to suit.
Example HTML Popup Window Code:
||Open a popup window|
Automatically Center Your Popup
The following page has code for automatically centering your popup in the middle of the users' window, as well as other little snippets of code.
If you need to automatically center the popup on the screen, check it out.