auto set homepage/bookmark

I need a script that will automatically set the current page as home page...it should work on iexplorer and firefox that would I need it to be done in 2 ways. 1. as soon as the user enters the site It would prompt user if he would like to set it as home page. (if there is that site home page than it will not prompt) 2. It would do this without notifying the user. additianal requirements, an additional button to set this site to the homepage manually by pressing a "make this my homepage" button. and also for the browser to set the page in the chache so it wont need to reload it from the internet every time the homepage is pressed.