I have the following VB script which changes the color of the cell based on
its
value.
When the value changes, the color doesn't change at the moment. I need to
double click on the cell, for the color to change.
How can i make it refresh automatically? Is there a problem with the code?

This is my code.

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("A1:AQ120")) Is Nothing Then
Select Case Target

Case Is = "A"
icolor = 38
Case Is = "B"
icolor = 38
Case Is = "C"
icolor = 35
Case Is = "D"
icolor = 36
Case Is = "E"
icolor = 39
Case Is = "F"
icolor = 35
Case Is = "G"
icolor = 37
Case Is = "H"
icolor = 34
Case Is = "I"
icolor = 40
Case Is = "J"
icolor = 40
Case Is = "K"
icolor = 34
Case Is = "L"
icolor = 34
Case Is = "M"
icolor = 34
Case Else
'Whatever
End Select

Target.Interior.ColorIndex = icolor
End If

End Sub