vb.net messagebox

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If MessageBox.Show("记录删除后，将不能恢复！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning) Then
Call deletebook()

Else
Button1.Dispose()

End If
End Sub
deletebook()是删除程序，怎样在删除按钮那里弄个提示框，是的话则执行，否则不执行呀。我这个程序无论是还是关闭都执行。实现不了我要的效果

If MessageBox.Show("记录删除后，将不能恢复！", "警告", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) = DialogResult.OK Then
Call deletebook()
Else
Button1.Dispose()
End If