I am having some difficulty with data validation and not sure how best to approach the problem. On my spreadsheet I have a drop down list with 5 selections, depending on what is picked from this list will either set a default value to another field or present a list of options to choose from. For example:

If I select 1 in column A, I want column B to display a default value of "hour" and not allow it to be changed.
If I select 2 in column A, I want column B to allow me to either pick minute or second, but only pick one of those 2 values
And so on for values 3, 4 and 5 in column A.

I have tried using an IF formula, but this will only work for single values (unless I am missing something) so will not force a user to pick one of 2 values. I have tried looking at Data Validation but cannot figure out how to get it to either populate a field with a default value (see "hour" above) or restrict the input to a list of values.

Any suggestions? I am not opposed to using VBA, but do not want to have to force end users into running macro's.

Thanks.