Restrict data entry if preceeding cell value is greater than or blank

[GreggTO]

Hi there -

I'm building a worksheet that a group can use to track task completion dates. The tasks are in sequence and are listed in the top row, so each cell can only have a date value greater than the one to the left of it: A2 is greater than A1 and so on. I have used data validation to restrict entry with the following settings:

Allow: Date,
Data: greater than or equal to,
Start date: <cell reference to the immediate left>.

However, it still seems to be possible to enter a date if the cell to the immediate left is blank. This interrupts the sequence.

Is there any way to have two validation criteria on the same record, or is there another way to stop users from entering a date value when the preceeding cell doesn't have one?

Thanks in advance for whatever assistance you can provide.

[mrice]

You might try something like

=MIN(DATEVALUE("1/1/9999"),C6)

as you validation criterion. The empty cell should be ignored.

[GreggTO]

Thanks Martin -

I'm not sure how that would prevent the user from entering a value if the preceeding cell is empty. In this case, if C6 is NULL, I can still enter a value in D6.

Gregg