Pop window array

Hi
Am just trying to play around with a pop up window via flash.
I can pop the object listed in the var: my_image_var
but want to have a certain ammount more control over the window eg positioning and etc.

This is what I would think should work but does not for some reason.
Any suggestions would be great

thanks

cont.zoomer.onPress = function(){
getURL(“javascript:popUp(‘my_image_var’,300,450)”, “_self”);
}