>>>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.