Messagebox doubt in .net 2.0 framework

hi all,

I am filling a datatable in my windows appln.The data table looks like this

date             product

aug 2010       ABC-1

aug 2010       XYZ-1

aug 2010       MNO-2

aug 2010       WOR-4

sep 2010       XYZ-2

sep 2010       RES-3

sep 2010       WOR-4

..........          ............

I want to display a message box on button click in this format

aug 2010 - ABC-1,XYZ-1........

sep 2010 - XYZ-2,RES-3.........

only the first 2 products for each month should be displayed rest should be truncated for each month.

I hope i have explained my problem clearly.

PLZ help me

thanks in advance