Data validation doesn't force a user to make an entry - it only restricts
what can be entered. You are basically asking to format all cells except
the 3 in question with data validation that will not allow entry unless one
of the cells in question has an entry. This can be checked with

=counta(A1,A2,B3)0

for example, but still doesn't force an entry - but if applied to all other
cells would prevent entry until it is met.

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Regards,
Tom Ogilvy

"Hemant_india" wrote in message
...
hi
i have thre columns of which at least one should contain some text
how do i validate such condition?
thanks

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hemu