__Data__

From file 1

Alan,Bloggs,06/11/2009,11/30/2011
David,Smith,06/08/2009,09/30/2012
Rosario,Anotherone,06/05/2009,11/30/2011
Angela,Madeupname,06/11/2009,07/31/2010
Ugochukwu,Smith,06/01/2009,10/31/2012
Amarjit,Patel,08/19/2008,11/30/2011
Julie,Schmidt,05/01/2009,09/30/2012
Waseem,Alder,06/11/2009,11/30/2011
...
for another 580 lines.

File 2
abc,Alan,Bloggs,06/11/2009,11/30/2011,morefields,...
cde,David,Smith,06/08/2009,09/30/2012,morefields,...
abc,Rosario,Anotherone,06/05/2009,11/30/2011,morefields,...
acd,Angela,Madeupname,06/11/2009,07/31/2010,morefields,...
cde,Ugochukwu,Smith,06/01/2009,10/31/2012,morefields,...
tla,Julie,Schmidt,05/01/2009,09/30/2012,morefields,...
tl,Waseem,Alder,06/11/2009,11/30/2011,morefields,...

__End of Data__