make cell red if other cell is blank

[Opgelost]

Dears,

I would like to do the following with conditional formatting:

Fill the cell (e.g. a3) with the RED colour if the corresponding cell in column B (e.g. b3) is blank.

Kindly advise.

Thank you!

 

[JoeMo]

1. Select all the cells in col A you want to format (let's assume you start at A1 for this example)
2. Home>Styles>Conditional Formatting>New Rule>Use a formula
3. Formula is: =$B1=""
4. Select red fill as the format
5. Press OK