submiting a form using javascript

Hi friends,

i am looking for a solution in javascript by which i can change the action part or attribute of a form in html and then submit it at run time

i mean to say i want to sent a form changing its action attribute and some of its field's values at runtime .
Any help will be greatly appreciated .Thanks in advance

document.forms[0].action = 'a_different_page.asp';
document.forms[0].submit()