Data in cells

[bogi sigurdsson]

I have to cells in the same row A10 and B10 

If there is entered data in A10 there should not to be allowed to enter data in B10 and vice versa.

It should only allowed data in one of the cells.

How can I prevent this?

[#2]

@bogi sigurdsson Use conditional formatting (CF) for this.

In A10 the CF rule should be =ISBLANK(B10) and in B10 it should be =ISBLANK(A10)

Example attached

[#3]

You mean data validation?

[#4]

@bogi sigurdsson Sorry! Yes, Data Validation