I wasn't arguing that the Quran is based on the Bible. I was mentioning that the Quran itself states that Jesus (Isa) foretold of the coming of Muhammad.

Why would Jews and Christians put references to an Arab prophet in their own books? As a former Christian I was very curious about this, because if there were references in the Bible about Muhammad, it would serve as strong evidence that the Quran is true.

It also serves to demonstrate that the Bible was originally written or inspired by someone or something other than Jewish and Christian clergy.

The Islamic perspective on this is that all the prophets were inspired by God (Allah). Any similarities which occur between Islam and older religions, is because they have the same origin - Allah. Any differences which we see, are the result of human tampering with the older texts.

I wrote a bit of a book about this whole study, if anyone is interested in reading it:
http://www.schmidt-gallery.com/Bible_in_islam_v008.pdf