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Can I do the following with Javascript?

My state has a web site that can be used for online filing for
unemployment benefits. Every week I have to go to the site and fill in
a form, checking off the same boxes each time. I'd like to automate
this.

I need to load the URL for the login page into the browser, fill in my
username and password, and submit the form. From that page I need to
follow a link to file for benefits. There I need to fill in the form by
checking a few boxes and submit the form. This brings up another form
where I have to confirm the entries. Then finally I can select the
Logout link.

How would I go about automating that with Javascript? I don't need
someone to write the whole thing, just provide the basic processes. I
had a similar question a few weeks ago, when I was trying to create a
bookmarklet to open my web banking page and prefill the account number,
but I was never able to solve it (I'm making do with two bookmarks -- a
regular one to open the page, and a bookmarklet to fill in the account#
field once the page is loaded). This makes me think that my plan for
the unemployment page won't work either, but there's no harm in asking.