Comparing keys in two tables

[Aaron Fischer]

Greetings!

I have a problem that it seems would best be solved using  
subqueries.  However, I am working on a server that is running MySQL  
3.23.58, so subqueries are not available to me.

What I am trying to do:
I have two tables, each containing approximately 37,000 records.  I  
want to compare the index field in Table A to the index field in  
Table B.  I would like to see all records where the index in Table A  
does not exist in Table B.

Thoughts?  Suggestions?

Much appreciated!

-Aaron