Hiding rows based on input parameter

[Niss1]

In my excel sheet I have a drop down box.
If the user selects "Parameter1" i would like to unhide the next 5 rows, if he chooses something else then i would like to hide those 5 rows.

This happens several times in my worksheet and i would like to have something where i do not need to hardcode the row numbers for each case.

 

[Weaver]

If you have lots of validation cells, you could try

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If hasValidation(Target) Then
        Application.EnableEvents = False
            With Target
            .Offset(1).Resize(5).EntireRow.Hidden = .Value <> "Parameter1"
        End With
        Application.EnableEvents = True
    End If
End Sub
Function hasValidation(ByVal rng As Range) As Boolean
    On Error GoTo noValidation
    hasValidation = (rng.Validation.Type = 3)
noValidation:
End Function

You can add more without changing the code.