>>>>Not tested, but must work:
>>>>
>>>>Test the document.body.scroll property to know if scrollbar are on or off
>>>>and, if on, compare the document.body.scrollHeight (visible area)
>>>>with the document.body.clientHeight (window or frame height).
>>>
>>>It doesn't work when the window has been created with window.open(). That's the only think I can see.
>>
>>Can you explain a bit more what you are trying to do?
>
>With a window that is created with window.open(), I need to know, within the script of that new window, if a scrollbars is present.
>
>So, from this window for example, I may use the Tools menu to select the color. The color window has been launched with window.open(). That new window runs a script to center itself and stuff like that. From that script, I need to know it.

I dont know how to get this info. :-(

But since the width of a scrollbar was around 20 px, you can average your calculation to 10 px to set the window really near the center of the screen...