The code in Figure 6-3 does a good job of opening and centering a window containing No Starch Press's home page. But what if you wanted another link to open and center a different window with a different URL in it—Webmonkey's, for example?
One approach would be to write a second function that looks just like the first one, the only difference being that you'd replace the line
var the_window = window.open('http://www.nostarch.com/','the_window','height=200,width=200');
with the line
var the_window = window.open('http://www.webmonkey.com/','the_window','height=200,width=200');
This would work fine, but it's not a good idea to have two functions that do almost exactly the same thing. First of all, it's wasteful. If you could ...