I get the following error, "Next without For". How do I change my code to
fix it?

'Format Colums which are John
For a = 4 To 31
If Cells(a, 1).Value = "John" Then
For b = 2 To 32
If Cells(2, b).Value = "Fri" Then
Cells(a, b).Select
With Selection.Interior
.ColorIndex = 0
.Pattern = xlGray8
.PatternColorIndex = xlAutomatic
End With
Next b
End If
Next a

MsgBox "Formatting Complete"
Exit Sub
Error:
Exit Sub
End Sub