Programmatically determine SharePoint 2007 authentication mode

authmode.cs

//Is there a way to programmatically determine if a SharePoint 2007 web application is using Forms authentication? I guess one way might be to read it from the web.config but I was wondering if there is some property exposed in the API.

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);
    string g = base.Request.QueryString["WebAppId"];
    this.webApp = (SPWebApplication) SPConfigurationDatabase.Local.GetObject(new Guid(g));
    this.zone = (SPUrlZone) Enum.Parse(typeof(SPUrlZone), base.Request.QueryString["Zone"]);
    this.lb_Zone.Text = SPHttpUtility.HtmlEncode(SPAlternateUrl.GetZoneName(this.zone));
    SPIisSettings iisSettings = this.webApp.IisSettings[this.zone];

    // CODE ELIDED

        if (AuthenticationMode.Windows != iisSettings.AuthenticationMode)
        {
            if (AuthenticationMode.Forms != iisSettings.AuthenticationMode)
            {
                // CODE ELIDED
            }
            else
            {
                this.rdo_authForms.Checked = true;
            }

            // CODE ELIDED
       }
}