How to disable past date in ajax control toolkit calendar extender

Goodmoring,

I have two textboxwithcalendar extenderinajax.
I would likeonce you select thefirst datefrom the first textboxinsecond textboxthere are onlythedate >of the first textbox.

How can I do??

First Textbox with calendar

<asp:TextBox  ID="tb_dal" runat="server" style="margin-left: 3px"></asp:TextBox>&nbsp;</td>
           
<asp:CalendarExtender ID="CalendarExtender1" TargetControlID="tb_dal" runat="server"
                Format="dd.MM.yyyy" FirstDayOfWeek="Monday" DaysModeTitleFormat="dd.MM.yyyy"
                TodaysDateFormat="dd.MM.yyyy"  > </asp:CalendarExtender>

second Textbox with calendar

<asp:TextBox ID="tb_al" runat="server" Width="125px"></asp:TextBox></td>

        <asp:CalendarExtender ID="CalendarExtender2" TargetControlID="tb_al" runat="server"
                Format="dd.MM.yyyy" FirstDayOfWeek="Monday" DaysModeTitleFormat="dd.MM.yyyy"
                TodaysDateFormat="dd.MM.yyyy" > </asp:CalendarExtender>