ASP.NET

Validate Date of Birth

protected void Page_Load(object sender, EventArgs e)
        {
              rvSearchDOB.MaximumValue = DateTime.Now.ToString("d");
        }

<asp:TextBox runat="server" ID="txtSearchDOB" />&nbsp;<asp:Image ImageUrl="~/Images/calender_btn.png"
                    runat="server" ID="imgCal" ImageAlign="AbsMiddle" />
                <ajaxToolkit:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="txtSearchDOB"
                    Format="d" PopupButtonID="imgCal" />
                <asp:CompareValidator ErrorMessage="Invalid date format. Use (mm/dd/yyyy)" Display="None" ID="cvSearchDOB"
                    ControlToValidate="txtSearchDOB" Operator="DataTypeCheck" Type="Date" runat="server" ValidationGroup="grpSearchSubmit" />
                <ajaxtoolkit:ValidatorCalloutExtender ID="vcSearchDOB" runat="server" TargetControlID="cvSearchDOB"
                    PopupPosition="TopLeft" Enabled="True"  />
                <asp:RangeValidator ID="rvSearchDOB" runat="server" ControlToValidate="txtSearchDOB"
                    MinimumValue="1/1/1900" MaximumValue="1/1/2100" Type="Date" Text="Invalid Date"
                    Display="None" ValidationGroup="grpSearchSubmit" />
                <ajaxtoolkit:ValidatorCalloutExtender ID="vcretxtSearchDOB" runat="server" TargetControlID="rvSearchDOB"
                    PopupPosition="TopLeft" Enabled="True" />