I think you'll need to post the code of both the frame definition and the 
JavaScript. There are a lot of possible reasons why MainFS1 is not an object.

Imar


At 11:43 PM 12/10/2000 -0800, you wrote:
>Thanks for this.
>
>I now get the error MainFS1 is not an object. MainFS1 is the name of the
>frame (with exact case).
>
>Any Ideas.
>
>Regards
>
>Andy Green