使用javascript将DIV添加到弹出窗口

So I have an HTML document containing CSS that defines the layout of a page of DIVs. I want to open a new window and add DIVs to this window containing info from an array. document.write will not work because it erases the existing page and thus removes the CSS. I have tried newwindow.document.body.appendChild() but nothing ever shows up. What am I missing?So I have an HTML document containing CSS that