Excel 2007 Macros based off Data Validation list to populate rows

See the attached workbook.

I put the following code in the sheet module where the data is.

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Dim ws As Worksheet

Set ws = Application.ActiveSheet

If Not Application.Intersect(Target, Range("C35")) Is Nothing Then

    If Range("C35").Value = "No" Then
        ws.Rows(37).Hidden = False
    Else
        ws.Rows(37).Hidden = True
    End If

End If

End Sub

I also changed how the dropdowns are populate. I assigned cells K30, K31 and K32 as the source for the list. I did this to give the user the ability to select a blank value. The way the dropdown was in the original file had it so the cell started blank but once the user selected Yes or No they then had to use the delete key to reset the cell to blank.