What I usually do in a case like that is to use Conditional Formatting to
color the cells RED if they are blank, (ie = < )and they turn white when
data is entered in them, then on the next function that depends on that
data, say a SUM function, use an IF to condition it, such as.........

=IF(COUNT(A1:A10)=10,SUM(A1:A10),"Red Cells must contain values")

Vaya con Dios,
Chuck, CABGx3


"Chris" wrote in message
...
Hi, can some one tell me if there's any way I put put some validation or
enforcement in a cell, where users HAVE to input something and it CANT be
left blank ? Thanks