what's the real difference between certification of platform 1.4 and 1.2?

I havn't decided which exam should take, certified programmer for Java 2 platform 1.4 or platform 1.2?

It looks the pass score of 1.4 is lower than 1.2, but probably the difficulity of 1.4 is

increased?

Anyone can tell the real difference of them? And please give the suggestions about which books or materials I should buy or download to prepare for this exam.

Thanks a lot!

Joan

[418 byte] By [pelhama] at [2007-10-1 4:35:12]