Unexpected Result When Used Onsubmit="alert(this.action)"

I have a form which I need submit using ajax. I already got all the needed query from that form, but when I tried get the action address I got [object HTMLInputElement] instead of expected address blah.php.

Here is a quick example to demonstrate this behavior:

Code:

The problem is that I named the button as "action" and this.action is returning the button object instead of the action of the form.

I can't remove the form element with name "action" from that form because of the script that accepts the data, but I need get somehow the form's action (url).