document.formname.action should work in all browsers. So does
document.forms.action = "whateverURL";
this.form.action = "whateverURL";
Check you do not have a form field named "action". If you do rename that field.
All advice is supplied packaged by intellectual weight, and not by volume. Contents may settle slightly in transit.
All the code given in this post has been tested and is intended to address the question asked.
Unless stated otherwise it is not just a demonstration.
Last edited by Philip M; 10-10-2012 at 09:43 AM..