As I stated earlier, the prototype.js library is too large for just using AJAX. In its current version (1.4.0_pre10) it weighs 36KB and contains lots of other features that are most probably not needed when just dealing with AJAX. I have therefore created a smaller version just for AJAX, based on 1.4.0_pre10: pt.ajax.js 8.9K It now has only a quarter of size and still provides some nice features s