99132 Javascript button in Oscommerc

Hi I have an oscommerce site, and am having horrendous problems with customers clicking the confirm order button twice, thus duplicating the order. I need some javascript programming to 1) stop the order going through twice (disable the button after clicking) 2) change the button to show, processing order... please wait when clicked. Im not sure if the 2 can be done together, but if only one can be implemented, i would like the 1st one. This is very simple, as their are various scripts that will do this for free, but I dont know how to program them in the script is attached, and the alteration is on line 343