intersection of 2 dataframes

[jdakin@OVERWEY.demon.co.uk]

I have two different dataframes, each with exactly the same columns. I wish to 
identify rows of data which are common to both.  

Intersect only applies to vectors.  I could apply intersect to sequentially to 
different columns that each was identical but it seems a long way about.  Is 
there a neater solution ?

I'm using Splus 6.1.  Many thanks for any advice.
Jonathan Dakin