protected void OnPreScaleHscaleValueChanged(object sender, System.EventArgs e)
{
preScale_hscale.Value = Math.Round(preScale_hscale.Value);
value_label.UseMarkup = true;
if (preScale_hscale.Value > 1)
value_label.Markup = "<b>" + (1.0 / preScale_hscale.Value * 100).ToString("0.0") + "%</b>";
else
value_label.Markup = "<b>" + (1.0 / preScale_hscale.Value * 100).ToString("0") + "%</b>";
}