I want to hide or show 3 columns depending on the
selection made from a drop-down data validation list. I
can only get the column that was selected prior to making
a different selection from the list to hide. I don't
understand why the columns specified in the code won't
hide, so any help I can get with this will be great.
Also, this is a worksheet change event; I'm not sure if
that's the best way to go with this. Here's the code I've
been using; try not to laugh too hard:

Sub Worksheet_Change(ByVal Target As Excel.Range)

If Application.Intersect(Target, Range("Plan Costs!e1"))
= "Hi-Low" Then
Exit Sub
End If
If Application.Intersect(Target, Range("Plan Costs!e1"))
= "EDLC" Then
Sheets("Period 1").Select
Columns("M:O").Select
Selection.EntireColumn.Hidden = True

End If

End Sub