Adding Custome validation Message at Screen side in LightSwitch 2011

I have small lightswitch application having CreateNewUser Screen.

Screen fields comes from Datatable added in DataSource, I have made all Validattion of fields at DataSource side However i have added one Custom Control in the screen named : Re-TypePassword.

Whenever user click on save button I want to match the Password and Re-TypePassword and want to prompt user a validation message if Password and Re-TypePassword are different.

how can i display that validation massage ? ( I mean i want to add validation message to Summary of messages that appears at the top of screen)

Thanks

One way is to add the -re type password- field to the database, then you can use the usual validation.

Not the best way, but it's a way :)

Conditional validation............... http://forums.asp.net/t/1924941.aspx?Conditional+Validation+using+DataAnnotation

[RequiredIf("isSelected", true)]
public class RequiredIfAttribute : ConditionalValidationAttribute
{
    protected override string ValidationName
    {
        get { return "requiredif"; }
    }
    public RequiredIfAttribute(string dependentProperty, object targetValue)
        : base(new RequiredAttribute(), dependentProperty, targetValue)
    {
    }
    protected override IDictionary<string, object> GetExtraValidationParameters()
    {
        return new Dictionary<string, object> 
    { 
        { "rule", "required" }
    };
    }
}

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false)]
public abstract class ConditionalValidationAttribute : ValidationAttribute, IClientValidatable
{
    protected readonly ValidationAttribute InnerAttribute;
    public string DependentProperty { get; set; }
    public object TargetValue { get; set; }
    protected abstract string ValidationName { get; }

    protected virtual IDictionary<string, object> GetExtraValidationParameters()
    {
        return new Dictionary<string, object>();
    }

    protected ConditionalValidationAttribute(ValidationAttribute innerAttribute, string dependentProperty, object targetValue)
    {
        this.InnerAttribute = innerAttribute;
        this.DependentProperty = dependentProperty;
        this.TargetValue = targetValue;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // get a reference to the property this validation depends upon
        var containerType = validationContext.ObjectInstance.GetType();
        var field = containerType.GetProperty(this.DependentProperty);
        if (field != null)
        {
            // get the value of the dependent property
            var dependentvalue = field.GetValue(validationContext.ObjectInstance, null);

            // compare the value against the target value
            if ((dependentvalue == null && this.TargetValue == null) || (dependentvalue != null && dependentvalue.Equals(this.TargetValue)))
            {
                // match => means we should try validating this field
                if (!InnerAttribute.IsValid(value))
                {
                    // validation failed - return an error
                    return new ValidationResult(this.ErrorMessage, new[] { validationContext.MemberName });
                }
            }
        }
        return ValidationResult.Success;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule()
        {
            ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
            ValidationType = ValidationName,
        };
        string depProp = BuildDependentPropertyId(metadata, context as ViewContext);
        // find the value on the control we depend on; if it's a bool, format it javascript style
        string targetValue = (this.TargetValue ?? "").ToString();
        if (this.TargetValue.GetType() == typeof(bool))
        {
            targetValue = targetValue.ToLower();
        }
        rule.ValidationParameters.Add("dependentproperty", depProp);
        rule.ValidationParameters.Add("targetvalue", targetValue);
        // Add the extra params, if any
        foreach (var param in GetExtraValidationParameters())
        {
            rule.ValidationParameters.Add(param);
        }
        yield return rule;
    }

    private string BuildDependentPropertyId(ModelMetadata metadata, ViewContext viewContext)
    {
        string depProp = viewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(this.DependentProperty);
        // This will have the name of the current field appended to the beginning, because the TemplateInfo's context has had this fieldname appended to it.
        var thisField = metadata.PropertyName + "_";
        if (depProp.StartsWith(thisField))
        {
            depProp = depProp.Substring(thisField.Length);
        }
        return depProp;
    }
}