Comparing two dates.Ensure Enddate is greater then start date.

try this:

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

<asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="TextBox1"

ErrorMessage="CompareValidator" Operator="GreaterThanEqual" Type="Date"></asp:CompareValidator>

and set CompareValidator1.ValueToCompare on page load as:

CompareValidator1.ValueToCompare = Convert.ToDateTime(TextBox2.Text);

I know this .I am working with Asp.net MVC2.0 .So iam looking to create a custom validation class using ValidationAttribute .

Will this work? Might require some modification, untested
public class DateEqualityAttribute : ValidationAttribute
    {
        public DateEqualityAttribute(DateTime startDate, DateTime endDate)
            : base()
        {
            StartDate = startDate;
            EndDate = endDate;
        }

        public override bool IsValid(object value)
        {
            if (value != null)
            {
                return StartDate < EndDate;
            }
            return true;
        }

        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
    }

I had the similar thought.Would you please let me know how to use this DateEqualityAttribute.Because my ViewModel has two properties  as below

 public class FundTypeEditViewModel : ViewModelBase
    {
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
    }
so how to call the DateEqualityAttribute in my ViewModel

Thanks