i need help for asp.net calendar control

See more:

C#

ASP.NET4

Dear fellows.I have to restrict access or selection to the date of any previous Day,Month,Year in the Calendar Control except today's or any day(s) after tomorrow

protected void Calendar1_DayRender(object sender, System.Web.UI.WebControls.DayRenderEventArgs e)

{

    if(e.Day.Date.ToShortDateString() <= DateTime.Now.ToShortDateString())

    {

        e.Cell.BackColor=ColorTranslator.FromHtml("#a9a9a9");

        e.Day.IsSelectable=false;

    }

}

this approach just change the back color and not disabling selection.I first extracted the days in integers separately because if also has some errors.Anyways;it doesn't work

protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
    {
        DateTime pastday = e.Day.Date;
        DateTime date = DateTime.Now;
        int year = date.Year;
        int month = date.Month;
        int day = date.Day;
        DateTime today = new DateTime(year, month, day);
        if (pastday.CompareTo(today) < 0)
        {
            e.Cell.BackColor = System.Drawing.Color.Gray;
            e.Day.IsSelectable = false;
        }
    }

that approach didn't work as well