'ello all,
ok let's say i've got a slide with 4 frames. i've got an object in frame 1 hidden until called. i would like that object to show ONLY if the link back to frame 1 comes from frame 3 ONLY. how may this be possible?

One suggestion: Define a variable, make it 0 (zero) and on an object in frame make it 1.

Show you object only if this variable is 1.

Any action using DISPLAY can be set to change the visibility of an item on another page. So the show hide bit is already there.
What you're really after is how to define and set variables to trigger a display event.
So you have your variable called say showit with a value of 0. You have a frame level onload action associated with frame 1 that in outline looks like this:
# variable define showit with a value of 0 (module wide)
# Display is set to hide the object
# if showit isnot equal to 1
# display is set to show the object
When frame 3 opens there is an onload action
# variable showit value = 1
so skip back to frame 1 and the variable is now equal to 1 and the object is displayed.
The syntax for the if variable = is in the help docs

thanks barend and nick.
i'm trying this variable thing [:p]

Or even simpler
set a display action on frame 1 to hide the object,
Set a display action on frame 3 to show the object,
Go back from frame 3 and the object should now be visible.