detecting open windows with js

[mbenton]

How do I tell if a named window is open using javascript in another window?

Then how can I get the value of a form field from the named window?

[ray326]

I think you can do that only if there is a close relationship (opener/parent) between the windows. I.e. if window A opens windows B and C then B and C will not know of each other but A/B and A/C will.