How do I auto-submit a form with Greasemonkey?

I'm trying to autosubmit a form with greasemonkey however I'm not sure how to do it with this button. The button seems to have the following properties

a class="blue-button" href="javascript:void(0)" onclick="Form.submit(this);"

and the only form I see above is

<form xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://www.blizzard.com/ns/store" action="/account/management/add-game.xml" autocomplete="off" method="post">

The page is here you ca开发者_开发问答n use "email9999@trash2009.com" and "a1a1a1a1" as a login.

document.getElementsByTagName('form')[0].submit();

Note that this will only work if the first form on the page. You can increase the array index to [1] if you need to, or loop through the array looking for the right form.

After you have got the username and password fields filled in, do this:

unsafeWindow.Form.submit(document.getElementsByClassName('submit')[0]);

Check unsafeWindow documentation here.