Macros code to erase data

Grettings people

just need someone to help me with completing my macros code. I am trying to get a cell to display a code when i enter a number into another cell. I have most of the code but i am looking to add in another line that enables me to delete all data in the output cell when the input cell is blank.
here is what i have so far

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
  If Not Intersect([D7,Target) Is Nothing Then
     Application.EnableEvents = False
     Cells(Target.Row, 2) = Now
     Application.EnableEvents = True
  End If
End Sub

As i mentioned earlier, once the input cell is blank it should erase all data in the output cel.
Sorry guys, I know this seems easy but i am having a really bad mental block today.

appreciate the help
cheers