Hi everybody,

I've added new conditional tab to my FormView. I'm getting System.InvalidCastException was unhandled by user code
Message="Specified cast is not valid."

at System.Web.UI.Control.OnDataBinding(EventArgs e)
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at System.Web.UI.Control.DataBind()
at System.Web.UI.Control.DataBindChildren()
InnerException:

I retrieve the data using LEFT JOIN, so my fields are NULL. Here is what I put on the ASPX

  <!-- 6th -->
                                <div id="info6" class="cl dn">
                                    <MembInfo:MembershipInfo ID="MembershipInfoRegular" runat="server" 
                                    BillQuaterly ='<%# Bind("BillQuaterly") %>' IsMember ='<%# Bind("IsMember") %>'
                                    PaymentMethod='<%# Bind("PaymentMethod") %>' StartDate ='<%# Bind("StartDate") %>' />
                                </div>
                                <!-- /6th -->

and this is my UserControl:

using System;
using System.Collections;
using System.Collections.Generic; 
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.ComponentModel;

public partial class Coordinator_UCD_MembershipInfo : System.Web.UI.UserControl
{
    #region Custom Properties
    ///
    /// <summary>The EditMode property is responsible for the Enabled style of the controls</summary>
    ///
    private bool editMode ;
    [Description("The EditMode property is responsible for the Enabled style of the controls"), DefaultValue(true),Category("User-Defined")]
    public bool EditMode
    {
        get { return editMode ; }
        set {
            editMode = value;
            clseditmode.SetEnabled(this.Controls, value);
        }
    }
    
    [Bindable(true, BindingDirection.TwoWay), Category("User-Defined"),DefaultValue(false),Description("Is User a Member?")  ]
    public bool? IsMember
    {
        get
        {
            return this.chkIsMember.Checked;
        }
        set
        {
            this.chkIsMember.Checked = Convert.ToBoolean(value);
        }
    }
    [Bindable(true, BindingDirection.TwoWay), Category("User-Defined"), DefaultValue(false), Description("Bill Quaterly?")  ]
    public bool? BillQuaterly
    {
        get
        {
            return this.chkBillQuaterly.Checked;
        }
        set
        {
            this.chkBillQuaterly.Checked = Convert.ToBoolean(value);
        }
    }
    
    [Bindable(true, BindingDirection.TwoWay), Category("User-Defined"), DefaultValue(""), Description("Payment Method") ]
    public string PaymentMethod
    {
        get
        {
            return this.ddlPaymentMethod.SelectedValue;  
        }
        set
        {
            this.ddlPaymentMethod.SelectedValue = value;
        }
    }
    [Bindable(true, BindingDirection.TwoWay), Category("User-Defined"), Description("Membership Begin Date") ]
    public DateTime? StartDate
    {
        get
        {
            return Convert.ToDateTime(this.txtMembershipStartDate.Text) ;
        }
        set
        {
            this.txtMembershipStartDate.Text = (Convert.ToDateTime(value)).ToShortDateString() ;
        }
    }
   #endregion
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

I'm not sure what should I do to make it work correctly with NULLs. I tried to change data types to be nullable, but this didn't help.

Thanks a lot in advance.