Delete cell value 'c4' automatically at the time of closing the file

Sub Auto_Close()
Range("C4").FormulaR1C1 = ""
End Sub

Hello mehmetcik,
Thank you but it's not working automatically. I have to manually run the macro by clicking. I want to delete the value of cells 'b4, c4' automatically at the time of closing the file. There is a little modification in cell address because in the morning I forgot to mention it. I want to delete the value of both cells 'b4, c4' automatically at the time of closing the file and make the cells blank. Next time when I open the file the cells must be blank for use.
Thanking you in anticipation.
Please see the attachment. I want to delete the names at the time of closing the file:
Baviskar 'b4' and Mukesh 'c4'

Mukesh