You can use a bit of javascript to do it. If you want to do it right when the form is submitted you can write an onSubmit handler for the form. i.e.:

  
onSubmit="top.document.displayframe.document.location.href='url';retur
+n true;"
[download]

(In IE, the syntax is a little different in NN).
Or to have the frame refreshed when the form destination is loaded add an onLoad event to the BODY tag of the destination document, similar to the above.

-pete
Entropy is not what it used to be.

Originally posted as a Categorized Answer.