Insert image dialog & filebrowserBrowseUrl problems not being a modal dialog

I set this to my aspx page I want to use to get url of an image to insert and this all works fine except it doesn't get displayed as a modal dialog so the user can close the insert image dialog which leaves my dialog hanging out there.  Even though I set config.filebrowserWindowFeatures = 'location=no,menubar=no,toolbar=no,dependent=yes,minimizable=no,modal=yes,alwaysRaised=yes,resizable=yes,scrollbars=yes';    The setting "dependant=yes" I guess only works for FireFox.  How can I get this to be displayed as a modal dialog?  Or how can I test if the insert image dialog has been closed??