VBA delete entire column contain certain value

Sub Macro1()
Dim LastColumn As Integer
LastColumn = Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox LastColumn
For y = LastColumn To 1 Step -1
Range("D5") = Mid(Cells(1, y).Value, 18, 7)
If Mid(Cells(1, y).Value, 18, 7) = "Q1 2011" Then
Columns(y).EntireColumn.Delete Shift:=xlToLeft
End If
Next y
End Sub