There are 2 parts to this. First blocking entry. This can be done with custom
validation. If I want to block cell A1 from entry if B1 has a value I would

Select Cell A1
Select Data | Validation | Custom
Add this formula
=B1=""
Select Ok
Now when B1 has a value A1 can not accept a value.
Do the Same for B1 with the formula =A1=""

To give a grey appearance you can use conditional formatting.
Select A1
Select Format | Conditional Formatting... | Formula is
=B1<""
Select Format | Pattern | Grey colour.
Repeate for Cell B1
--
HTH...

Jim Thomlinson


"LRay67" wrote:

I have this spreadsheet that if the user enters data in one cell I do not
want them to enter data into another cell. How can I accomplish this? Also
is there a way to put the cell that I don't want them to enter data into be
grayed out? Any help would be appreciated. Thanks