How can I force child windows to open on the same display as the parent?

I have a MacBook running Lion.

I use an external monitor. My work involves using a lot webapps and I frequently have popups I need to see and use. If I am on the external monitor, the popups always go the main laptop screen. (I have the laptop open.)

I use Chrome and haven't had much luck googling a fix because child and parent tend to bring up results about parental controls which is not my issue.

Any ideas?

Thanks.