Macro to Hide/Unhide rows based on the result of a formula

I am new to vba and have been searching for a way to automatically hide rows based on the result of a formula that returns either Y or N. The following code is what I have found but it only works if I enter Y or N. What do I need to change in order to make it work with a formula result rather than a manual entry? Any help would be appreciated.

Private Sub Worksheet_Change(ByVal Target As Range)
    If Range("M39").Value = "N" Then
        Rows("1:32").EntireRow.Hidden = True
    ElseIf Range("M39").Value = "Y" Then
        Rows("1:32").EntireRow.Hidden = False

    End If
End Sub

I've been playing with this and realize what my issue is, the Y/N is picked from a pull down on another worksheet "DATA_INPUT" and looks like this

Formula:

=Data_Input!B18

The worksheet "QUOTE" which I have the macro assigned to is a completely generated sheet with no input on it, it is simply a results page. I guess my question now is what do I need to change in order to allow this macro to work with a result from another worksheet?

I'm not sure what you mean by event handler. My experience with vba is about one day of doing Google searches. Could you show me what you are describing to do? Thank you for your help so far.