In Monday's blog, you saw how to make simple dependent data validation drop down lists. After creating the drop downs, you added some flexibility by using the IF function in the data validation formula.

Today you'll see a couple of problems that can occur when you refer to other cells in your data validation, and those cells are blank.

Invalid Entries Are Allowed

If you create a data validation formula that refers to another cell, and that cell is empty, users might be able to type invalid entries in the cell. For example, in the screen shot below, Buffalo was entered in cell B4. As you can see in the list in cell B5, that isn't one of the cities allowed when the adjacent cell in column A is empty.

Change the Ignore Blank Setting

To prevent people from entering invalid data when the cell referred to

Continue reading Ignore Blank Problems in Excel Data Validation