javascript error in filebrowser

I'm building a central admin for various sites that i'm building and i'm utilizing FCKEditor. After much research i found a solution to allow me to manage and maintain images through various domains however when it comes to the function to add the link of the file back into the popup using setURL i'm getting a javascript error in the filebrowser stating permission denied.

Any suggestions or ideas on how to solve this or has anyone come up with a full proof solution on have filebrowser control files,images on multiple domains?

Thanks