Need a simple javascript to do some automated tasks on a site

Hi i would need a simple script that can run on firefox(maybe greasemonkey addon) that as long the browser is open to see if i am logged in the page, and if not logged in to auto login, to click on a specific html <input name button> every ~2 hours , a random time between 1:50:00 and 2:11:00 (hours ,not time) and between1am to 8am (time +2 gmt ) the script to pause . i think the script will need the appropiate delays between actions to the script can run smoothly. I will post the website when i find someone who is interested in the project, its not that difficult you ll see!