VBA code for inserting unique text to each of 12 cells, when cells are blank - vba

Question

I am new to VBA and am severely stuck! I have 12 cells that I need to add specific text to, but only if the cells are blank. I managed to find code for 1 of them which is shown below:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Address = "$D$3" Then
If Target.Value = "Insert name of project (if known)" Then
Target.Font.ColorIndex = xlAutomatic
Target.Value = ""
Exit Sub
End If
End If
If [D3].Value = "" Then
[D3].Value = "Insert name of project (if known)"
[D3].Font.ColorIndex = 1
Else
[D3].Font.ColorIndex = xlAutomatic
End If
End Sub
However, seemingly I can only use this once per sheet. I need code that is similar to this that will hopefully do the same job. The remaining 11 cells need to have unique text.
Basically what I am trying to do is prompt the user to insert details in each of these cells and once the cells are filled, the form will be complete.
Any assistance is appreciated.
Hi, Apologies for the delay. This is the final edit, which works perfectly. I thought I was going to have an issue with 'undo' (CTRL+Z) but it seems to be fine now. Thanks again.
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim clls(1 To 12) As String
Dim msg(1 To 12) As String
Dim i As Long, addr As String, c As Range
clls(1) = "D3": msg(1) = "Insert name of project (if known)"
clls(2) = "D4": msg(2) = "Insert closest street address"
clls(3) = "H3": msg(3) = "Insert name of landowner (if applicable)"
clls(4) = "H4": msg(4) = "Insert name of Developer (if applicable)"
clls(5) = "H6": msg(5) = "Insert name of PM Co. (if different from above)"
clls(6) = "H7": msg(6) = "Insert name of Designer (if applicable)"
clls(7) = "H8": msg(7) = "Insert name of Constructor"
clls(8) = "L3": msg(8) = "Insert project number (if known)"
clls(9) = "L6": msg(9) = "Insert name"
clls(10) = "L7": msg(10) = "Insert submission date"
clls(11) = "D10": msg(11) = "Brief description of project: Adjustment, deviation, main upsizing, main extension, lead-in, lead-out, etc."
clls(12) = "D11": msg(12) = "Insert length of asset (number only)"
Set c = Target.Cells(1)
addr = c.Address(False, False)
For i = 1 To UBound(clls)
If addr = clls(i) Then
If c.Value = msg(i) Then
c.Font.ColorIndex = xlAutomatic
c.Value = ""
End If
Else
With Me.Range(clls(i))
If .Value = "" Then
.Value = msg(i)
.Font.ColorIndex = 1
End If
End With
End If
Next i
End Sub

Answer 1

Might need a bit of tweaking...
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim clls(1 To 5) As String
Dim msg(1 To 5) As String
Dim i As Long, addr As String, c As Range
clls(1) = "D3": msg(1) = "Message 1"
clls(2) = "D4": msg(2) = "Message 2"
clls(3) = "D5": msg(3) = "Message 3"
clls(4) = "D6": msg(4) = "Message 4"
clls(5) = "D7": msg(5) = "Message 5"
Set c = Target.cells(1)
addr = c.Address(False, False)
For i = 1 To UBound(clls)
If addr = clls(i) Then
If c.Value = msg(i) Then
c.Font.ColorIndex = xlAutomatic
c.Value = ""
End If
Else
With Me.Range(clls(i))
If .Value = "" Then
.Value = msg(i)
.Font.ColorIndex = 1
End If
End With
End If
Next i
End Sub