what's the code for just a popup window when you got to a site??? you know like popup ads that just popup out of no where!!!
You should be wary of using popups unless absolutely necessary. They are annoying and because of that, a large portion of the browser public has some sort of software to block popups.
Clicking a link, a form which will open in a new window is generally okay and won't be blocked, but a popup onload, for example will be blocked.
So basically what I'm saying if you MUST use a popup, be sure to tell the user that a new window will be opened.