SQL Query Question

This isn't game-related but something I'm stuck on at work, I need a quick answer and GD is the biggest coding community I know... The problem is pretty simple to describe: Table A & B both have a date field. I need a query/procedure which will do:

SELECT A.date, { max(B.date) where B.date < A.date}

Example:

A.date       B.date
======       ======
10/10/2006   01/01/1999
01/04/2007   12/12/2006

Result:
A.date       Max B.date < A.date
======       ===================
10/10/2006   01/01/1999           // the biggest date in B which is < than 10/10/2006
01/04/2007   12/12/2006

So each row contains the date of an A, and the biggest date in B which is less than this value. It seems like it should be so simple but I just can't get it to work in a query, and I don't know the syntax Sybase (the DB we use) has for writing procedures - if I were in Oracle I'd have given up and written a FOR loop by now... but a query would be neater anyway. Many thanks for any help. I posted also at DBForums.com - if anyone can recommend a great DB-related community that would be cool for future reference.