confusion with coldfusion

seriously, i don’t know why some people decided to use coldfusion 4.5: right now, i have to understand and enhance somebody’s coldfusion code to make it work for the company i work for. while trying to do that, i realize that most of the functions that i need now to speed up the code, are not available for version 4.5

is there anybody who has a good resource for coldfusion 4.5?

moving forward to more futuristic methods/technologies:
i found a nice one-chapter example of the new series by o’reilly: head rush AJAX.
I really like the style how this serie of books presents its content to the readers: easy, funny and nice to read and understand. I am really thinking of buying it.
Another one I am reading/using is this one:  head first design patterns.