Submitting form in a frame problem

[Pieter-Jan]

Hello

Our website has a form in a frame. When you click on the submit button the browser is redirected to an other page. This is the code:

WebResponse disclaimer=con.getResponse(url);
WebResponse frame=disclaimer.getSubframeContents("Down");
WebForm form=frame.getFormWithName("form");
WebResponse nextpage=form.submit();

However, when the submit() method is called, the following exception is generated.

NoSuchFrameException: No frame named Down is currently active

I have searched through the API and on the web, but I didn't find anything to set the active frame. How can this be solved?

Thanks in advance
Pieter-Jan