Windows should be able to be contained or restricted to a specific area. This can either be using parameters or by containing it to a parent object/DIV. Reasons: Windows can be dragged anywhere on the browser document and when maximized they take up the entire document. This is a problem if you have an area of the document that you always want to have visible. In my example, I have a toolbar at the top of the screen 25px high and I would like the windows to never move into that area so that it is always accessible.