Custom Web Control - HTML5 TextBox control for adding placeholder support

Html5TextBox.cs

    [DefaultProperty("Text")]
    [ToolboxData("<{0}:Html5TextBox runat=server></{0}:Html5TextBox>")]
    public class Html5TextBox : TextBox
    {
        string _placeholder = "enter value";

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("enter value")]
        [Localizable(true)]
        public string Placeholder
        {
            get
            {
                return _placeholder;
            }
 
            set
            {
                _placeholder = value;
            }
        }

        protected override void AddAttributesToRender(HtmlTextWriter writer)
        {
            writer.AddAttribute("placeholder", _placeholder);
            base.AddAttributesToRender(writer);
        } 
    }