You might want to consider using a div
element pop-up window that contains an iframe.
jQuery Dialog is a simple way to get started. Just add an iframe as the content.
Since many browsers block popups by default and popups are really ugly, I recommend using lightbox or thickbox.
They are prettier and are not popups. They are extra HTML markups that are appended to your document's body with the appropriate CSS content.
Plain HTML does not support this. You'll need to use some JavaScript code.
Also, note that large parts of the world are using a popup blocker nowadays. You may want to reconsider your design!
I can't comment on Esben Skov Pedersen's answer directly, but using the following notation for links:
<a href="javascript:window.open('http://www.websiteofyourchoice.com');">Click here</a>
In Internet Explorer, the new browser window appears, but the current window navigates to a page which says "[Object]". To avoid this, simple put a "void(0)" behind the JavaScript function.
This should work
<a href="javascript:window.open('document.aspx','mywindowtitle','width=500,height=150')">open window</a>
Source: Stackoverflow.com