One cannot call moveTo or moveBy on BYOND created popups. You can do it for window.open popups, but as you know that creates a new IE window, and the desire for this comes from wanting to make chromeless windows usable.
Code Snippet (if applicable) to Reproduce Problem:
usr << browse("<button onclick='window.moveTo(50,50);'>Move</button>", "titlebar=0;window=hello;can_resize=0")
Expected Results:
To have the window moved to 50,50
Actual Results:
Nothing happens.
Happens all the time, on all versions that I'm aware of.
Workarounds:
Nothing that isn't extremely hacky.
Your best bet is having an interface window that contains the browser element, using that, and then using winset() to alter the position using a javascript call.