The myPopup variable is a reference to the 'window' object of the new window. In the reverse, you would use the 'opener' object in the popup to refer to it's "parent".
Its true that the myPopup variable is reference to the child window but doing the document.write on the child window will not work, since document.write only works during onload, but if it does work the, contents of the whole child window page will be replaced by the text that you have written through the document.write in the parent window. Since the problem was assigning values to the child window from the parent window will have to do that using the DOM way.
[CODE] var popup = window.open(); popup.document.getElementById('elementFromChildWindow').value = 'value';//assuming that the element that is to be filled has an ID of 'elementFromChildWindow' this line should only be executed once the popup window has already been loaded. [/CODE]
@ricpApr 15.2007 — #Its true that the myPopup variable is reference to the child window but doing the document.write on the child window will not work, since document.write only works during onload .. [/QUOTE]
You are right, but from his original post that's what I actually thought he wanted.