again HELP: checking content in opener window with frameset

[JPL Verhey]

Hi,

With a script in a popup window, I want to check if certain content is
present in a page loaded into the frame "main" of the frameset in the
opener window.

I started with something like this (what happens when the considions are
met already works):

if (
...
&& opener.window.frames['main'] ........................???
...
)

....but have no idea how to proceed..and if this beginning is ok! Assume
there is an image <img src= /photo.jpg> in that page in the 'main' frame
of the opener window.. can I check that out with this script??

Or are there other elements/text strings to check on if images wont do
it?

Most appreciated in advance.
&^%(
Thnx