Matching cells with equal values

Originally Posted by LukeBhatia

06/05/2010 06/09/2010
06/05/2010 06/09/2010
06/05/2010 06/09/2010
06/05/2010 06/09/2010
06/05/2010 06/09/2010
06/05/2010 06/05/2010
06/05/2010 06/05/2010
06/05/2010 06/09/2010
06/05/2010 13/09/2010
06/05/2010 06/09/2010
06/05/2010 06/09/2010
06/05/2010 06/09/2010

Assuming your Data is A1:B10 and you had dates matching as above, what are you looking for? All the dates in Column A would match the two cells i've altered, how would you like that to show or do you wish only the cells that match in Column B to be highlighted?

If you would just like the column B data thats matching highlightes, Highlight the cells B1:B10, open Conditional Formatting, go to new rule, and paste this in =COUNTIF($A$1:$A$12,B1)>1 and format with a colour, then click ok