Why on earth am I getting this error????

[groston]

Based on some suggestions I have received from this board, I am rewriting my program using a DataGridView as opposed to an array of buttons. Basically, things are going okay, but the program needs to know if a cell clicked on was clicked with the left or right mouse button.

Based on some searching around, I came upon something that seemed like a reasonable answer. Here is the code (greatly simplified):

Public Class frmDGVTest
    Dim dgTest As New DataGridView

    Private Sub frmDGTest_Load(sender As Object, e As EventArgs) Handles Me.Load
        dgTest.ColumnCount = 9
        dgTest.RowCount = 9
        <etc>
    End Sub

    Private Sub dgTest_CellMouseClick(ByVal sender As Object, ByVal e As DataGridViewCellMouseEventArgs) Handles dgTest.CellMouseDown
        If e.Button = MouseButtons.Left Then
            <stuff>
        End If
    End Sub
End Class

The problem is that I get this error:

Error 1 Handles clause requires a WithEvents variable defined in the containing type or one of its base types.

I simply do not understand this since I essentially copied the code directly. What did I do wrong?