validation

hi,

I have a workbook with 2 sheets. In one sheet I have a calender and other
sheet just list of names. what i want to do is: In the calender sheet if i
have a name under a date and when i enter that date beside that name in the
sheet of name list, i want to have a message saying that he/she is on
vacation.

For eg:

In calender sheet

a1&b1(merge 2 cells) (date-05-05-2010)
a2-ganga
b2-ravi

In name list sheet
a1-ganga- if i enter 05-05-2010 then the msg should say ganga is on vacation
a2-ravi-if i enter 05-05-2010 then the msg should say ravi is on vacation

Thank you