Visual Basic - capturar el evento click de un boton en vb.net contenido en un gridview

Protected Sub GridView1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles GridView1.SelectedIndexChanged

	Try

	Dim Cnn As New SqlConnection(Session("CONEXION"))

	Dim Ds As New DataSet

	Dim Da As New SqlClient.SqlDataAdapter("Select * from TABLA " & _

	"where CAMPO=" & Me.GridView1.Rows(GridView1.SelectedRow.RowIndex).Cells(1).Text, Cnn) 'obtiene el dato del campo seleccionado con el click

	Da.Fill(Ds, "TABLA")

	Dim myDataView As DataView = New DataView(Ds.Tables("TABLA"))

	Dim sentencia As String

	sentencia = "delete from TABLA where CAMPO = " & myDataView(0)("campo"))

	Dim comando As New SqlClient.SqlCommand(sentencia, Cnn)

	Dim resultados As Integer

	Cnn.Open()

	resultados = comando.ExecuteNonQuery()

	Cnn.Close()

	Catch err As SqlException

		Me.label_error.Text = err.Message

	Catch err As Exception

		Me.label_error.Text = err.Message

	End Try

End Sub