I am not 100% of the question, but I think you are missing the css unit, like below (emphasis)
var newWidth = sym.$("Stage").width() - 268;
sym.$("Rectangle").css("width", newWidth +"px");
Have you tried the code in the resize event? Whenever you resize your browser, it will re-execute the code.
the code works i just want it to be chekked always and not only when composition rdy
tryed that but its jumpy
The problem is that any event that happens more often is going to be hugely inefficient and will probably end up firing far more often than you're going to need it to. Can you explain why you want it to execute so often? It seems to me that unless the browser size is constantly changing, you wouldn't need it to execute all the time.
i thought so ....
atm its jumpy when i have it as onResize because it looks like theres a short delay on it.
i have an example here: www.gerberfilm.dk its the scrolling box to the right