Is it Possible to fill in a form (php) and send it automatically when I want?

[sequero1]

Imagine you are asked to enter your username and password in a certain time (like the people in lost), but you want to make a script to do it automatically for you, is it possible?

The form is just two imput fields and a submit button.

Just load the page with the form, fill in the fields with your user and password, and submit the form.

Of course i have no access to the server where the form is.

Maybe it's very easy, but i dont know how to start.

Thanks in advance!!