RadValidationRule validationRuleNumberLess;
        RadValidationRule validationRuleNumberGreater;
        float numberMaximum;
        float numberMinimum;

        public RadForm1()
        {
            InitializeComponent();
            CultureInfo culture = new System.Globalization.CultureInfo("de-DE");
            System.Threading.Thread.CurrentThread.CurrentCulture = culture;
            System.Threading.Thread.CurrentThread.CurrentUICulture = culture;
            this.radMaskedEditBox1.Culture = culture;

            this.numberMaximum = float.Parse("9,999", culture);
            this.numberMinimum = 0;

            // set maximum
            this.validationRuleNumberLess = new RadValidationRule();
            this.validationRuleNumberLess.AddControl(this.radMaskedEditBox1);
            this.validationRuleNumberLess.Operator = Telerik.WinControls.Data.FilterOperator.IsLessThanOrEqualTo;
            this.validationRuleNumberLess.PropertyName = "Value";
            this.validationRuleNumberLess.ToolTipTitle = "Too big";
            this.validationRuleNumberLess.ToolTipText = "The value must be SMALLER than " + this.numberMaximum.ToString();
            this.validationRuleNumberLess.Value = (float)this.numberMaximum + 0.001D;
            this.radValidationProvider1.ValidationRules.Add(this.validationRuleNumberLess);
            this.radValidationProvider1.SetValidationRule(this.radMaskedEditBox1, this.validationRuleNumberLess);

            // set minimum
            this.validationRuleNumberGreater = new RadValidationRule();
            this.validationRuleNumberGreater.PropertyName = "Value";
            this.validationRuleNumberGreater.ToolTipTitle = "Too small"; // this.localToolTipTitle;
            this.validationRuleNumberGreater.ToolTipText = "The value must be BIGGER than " + this.numberMinimum.ToString();
            this.validationRuleNumberGreater.Operator = Telerik.WinControls.Data.FilterOperator.IsGreaterThanOrEqualTo;
            this.validationRuleNumberGreater.Value = (float)this.numberMinimum;
            this.validationRuleNumberGreater.AddControl(this.radMaskedEditBox1);
            this.radValidationProvider1.ValidationRules.Add(this.validationRuleNumberGreater);
            this.radValidationProvider1.SetValidationRule(this.radMaskedEditBox1, this.validationRuleNumberGreater);

            this.radLabel1.Text = "Minimum = " + this.validationRuleNumberGreater.Value + " Maximum = " + this.validationRuleNumberLess.Value;
        }

        public RadForm1()
        {
            InitializeComponent();
            this.radMaskedEditBox1.MaskType = MaskType.Numeric;
            this.radMaskedEditBox1.Mask = "n3";

            this.radMaskedEditBox1.ValueChanging+=radMaskedEditBox1_ValueChanging;
        }

        private void RadButton1_Click(object sender, EventArgs e)
        {
            this.Text = this.radMaskedEditBox1.Value + "";
        } 


        private void radMaskedEditBox1_ValueChanging(object sender, CancelEventArgs e)
        {
           e.Cancel = true; 
        }